Sample records for underwater breathing apparatus

Performance tests on a closed circuit, mixed gas underwaterbreathingapparatus are reported. The equipment is designed to provide a minimum diving duration of four hours at 1500 ft below sea surface; it senses oxygen partial pressure in the breathing gas mix and controls oxygen content of the breathing gas within narrow limits about a preset value. The breathing circuit subsystem provides respirable gas to the diver and removes carbon dioxide and moisture from the expired gas. Test results indicate undesirable variations in oxygen partial pressure with oxygen addition and insufficient carbon dioxide absorption.

Divers constitute a potential threat to waterside infrastructures. Active diver detection sonars are available commercially but present some shortcomings, particularly in highly reverberant environments. This has led to research on passive sonar for diver detection. Passive detection of open-circuit UBA (underwaterbreathingapparatus) has been demonstrated. This letter reports on the detection of a diver wearing closed-circuit UBA (rebreather) in an operational harbor. Beamforming is applied to a passive array of 10 hydrophones in a pseudo-random linear arrangement. Experimental results are presented demonstrating detection of the rebreather at ranges up to 120 m and are validated by GPS ground truth. PMID:23039570

Aerospace Design & Development, Inc.'s (ADD's) SCAMP was developed under an SBIR contract through Kennedy Space Center. SCAMP stands for Supercritical Air Mobility Pack. The technology came from the life support fuel cell support systems used for the Apollo and Space Shuttle programs. It uses supercritical cryogenic air and is able to function in microgravity environments. SCAMP's self-contained breathingapparatus(SCBA) systems are also ground-based and can provide twice as much air than traditional SCBA's due to its high-density capacity. The SCAMP system was designed for use in launch pad emergency rescues. ADD also developed a protective suit for use with SCAMP that is smaller and lighter system than the old ones. ADD's SCAMP allows for body cooling and breathing from the supercritical cryogenic air, requiring no extra systems. The improvement over the traditional SCBA allows for a reduction of injuries, such as heat stress, and makes it easier for rescuers to save lives.

A self-contained breathingapparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level.

Our initial study, [1], demonstrated that the primary originating source of vibration and subsequent acoustic emission from an underwaterbreathingapparatus is turbulent air flow pressure fluctuations occurring during the inhale phase of breathing. The process of energy release associated with the expansion of compressed air in the high pressure scuba tank, through the first stage regulator, results in a highly turbulent, unsteady, compressible air flow. The paper presents results of experimental investigation and fluid dynamic simulation of turbulence-induced acoustic emission. The simulation reveals complex supersonic flow within the regulator's valve and channel topology. The associated regulator's air turbulent pressure pulsations and underwater acoustic emission are observed in a broadband frequency range.

The rough, hairy surfaces of many insects and spiders serve to render them water-repellent; consequently, when submerged, many are able to survive by virtue of a thin air layer trapped along their exteriors. The diffusion of dissolved oxygen from the ambient water may allow this layer to function as a respiratory bubble or , and so enable certain species to remain underwater indefinitely. Maintenance of the plastron requires that the curvature pressure balance the pressure difference between the plastron and ambient. Moreover, viable plastrons must be of sufficient area to accommodate the interfacial exchange of O2 and CO2 necessary to meet metabolic demands. By coupling the bubble mechanics, surface and gas-phase chemistry, we enumerate criteria for plastron viability and thereby deduce the range of environmental conditions and dive depths over which plastron breathers can survive. The influence of an external flow on plastron breathing is also examined. Dynamic pressure may become significant for respiration in fast-flowing, shallow and well-aerated streams. Moreover, flow effects are generally significant because they sharpen chemical gradients and so enhance mass transfer across the plastron interface. Modelling this process provides a rationale for the ventilation movements documented in the biology literature, whereby arthropods enhance plastron respiration by flapping their limbs or antennae. Biomimetic implications of our results are discussed.

A new generation of 60-minute self-contained breathingapparatus was being introduced into the underground coal mining industry for use as respiratory protection during fires and mine disasters. Little field experience existed from which to predict the survivability of this new life-support equipment. A series of environmental tests was proposed consisting of exposure to heat, cold, shock, and vibration. Treated and untreated apparatus were evaluated and compared by use on human subjects and a mechanical breathing simulator. Results are reported. After field data have been collected, information may be able to be correlated with environmental testing and used as a predictor of survivability.

A completely submersible, remotely operated underwater suction device for collection of irradiated materials in a nuclear pool is disclosed. The device includes a pump means for pumping water through the device, a filter means for capturing irradiated debris, remotely operated releasable connector means, a collection means and a means for remotely maneuvering the collection means. The components of the suction device may be changed and replaced underwater to take advantage of the excellent radiation shielding ability of water to thereby minimize exposure of personnel to radiation.

Research is described which is directed toward the preparation of chemical oxygen sources which exhibited improved O2 storage and reaction characteristics when compared to potassium superoxide (KO2). The initial focus of the research was the preparation of calcium superoxide (Ca(O2)2) by the disproportionation of calcium peroxide diperoxyhydrate. the Ca(O2)2 was characterized by chemical, thermal, and x ray analyses. Several methods for scaling up the Ca(O2)2 syntheis process were studied. The reactivity of Ca(O2)2 toward humidified carbon dioxide (CO2) was evaluated and was compared to that of KO2 under flow test conditions approximating those existing in portable breathingapparatus. The reactivities of mixtures of KO2 and Ca(O2)2 or lithium peroxide towards humidified CO2 were also studied. Finally, an analysis of two commercial, KO2-based, self contained self rescuers was conducted to determine the potential weight and volume savings which would be possible if Ca(O2)2 or a mixture of KO2 and Ca(O2)2 were used as a replacement for KO2.

A portable coal mine rescue and survival equipment is reported that consists of a chlorate candle with a lithium hydroxide carbon-dioxide absorbent for oxygen generation, a breathing bag and tubing to conduct breathing to and from the man. A plastic hood incorporating a mouth piece for communication provides also eye protection and prevents inhalation through the nose. Manned testing of a prototype system demonstrated the feasibility of this closed circuit no-maintenance breathingapparatus that provides for good voice communication.

An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

The state of the art in portable oxygen breathing equipment is reported. Considered are self-containing as well as chemically generating oxygen sources and their effectiveness and limitations in mine rescue operations.

Pulmonary edema has been reported in breath-hold divers during fish-catching diving activity. The present study was designed to detect possible increases in extravascular lung water (EVLW) in underwater fishermen after a competition. Thirty healthy subjects were studied. They participated in two different 5-h fish-catching diving competitions: one organized in the winter (10 subjects) and one organized in the autumn (20 subjects). A questionnaire was used to record underwater activity and note respiratory problems. An increase in EVLW was investigated from the detection of ultrasound lung comets (ULC) by chest ultrasonography. Complementary investigations included echocardiography and pulmonary function testing. An increase in EVLW was detected in three out of 30 underwater fishermen after the competition. No signs of cardiovascular dysfunction were found in the entire population and in divers with an increase in the ULC score. Two divers with raised ULC presented respiratory disorders such as cough or shortness of breath. Impairment in spirometric parameters was recorded in these subjects. An increase in EVLW could be observed after a fish-catching diving competition in three out of 30 underwater fishermen. In two subjects, it was related to respiratory disorders and impairment in pulmonary flow. PMID:21535186

... following devices: (a) Two pressure-demand, open circuit, self-contained breathingapparatus, approved by... and Health (NIOSH) and having at a minimum a 30-minute air supply, a full face piece, and a...

A portion of Title 30, Part II, CFR calls for a Man Test, which is a series of regimens performed with a breathingapparatus. The respiratory responses to the tasks in the Man Test were established on coal miners and students. Based on these responses, the minimal metabolic requirements were derived for the use of breathingapparatuses with a service life of 30 minutes or more. PMID:1211359

... commencement of diving operations, at the umbilical or underwaterbreathingapparatus connection point for the..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

... commencement of diving operations, at the umbilical or underwaterbreathingapparatus connection point for the..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

... commencement of diving operations, at the umbilical or underwaterbreathingapparatus connection point for the..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

Knowledge regarding arterial blood pressure (ABP) values during breath-hold diving is scanty. It derives from a few reports of measurements performed at the water's surface, showing slight or no increase in ABP, and from a single study of two simulated deep breath-hold dives in a hyperbaric chamber. Simulated dives showed an increase in ABP to values considered life threatening by standard clinical criteria. For the first time, using a novel noninvasive subaquatic sphygmomanometer, we successfully measured ABP in 10 healthy elite breath-hold divers at a depth of 10 m of freshwater (mfw). ABP was measured in dry conditions, at the surface (head-out immersion), and twice at a depth of 10 mfw. Underwater measurements of ABP were obtained in all subjects. Each measurement lasted 50-60 s and was accomplished without any complications or diver discomfort. In the 10 subjects as a whole, mean ABP values were 124/93 mmHg at the surface and 123/94 mmHg at a depth of 10 mfw. No significant statistical differences were found when blood pressure measurements at the water surface were compared with breath-hold diving conditions at a depth of 10 mfw. No systolic blood pressure values >140 mmHg or diastolic blood pressure values >115 mmHg were recorded. In conclusion, direct measurements of ABP during apnea diving showed no or only mild increases in ABP. However, our results cannot be extended over environmental conditions different from those of the present study. PMID:19696356

Since the 1960s, decompression illness after breath-hold diving has been widely debated. The aim of this study was to detect circulating bubbles after breath-hold diving in underwater fishing divers. We used continuous Doppler (DUG, COMEX Pro) and transthoracic two-dimensional (2D) echocardiography (Kontron Sigma 1). This study was conducted during a training course organized by the French Federation of Subaquatic Sports at Minorca (Balearic Islands). Ten breath-hold divers performed repeated breath-hold dives for periods ranging from 2 to 6 h [mean maximum depth 35 meters of seawater (msw)]. A dive computer (Maestro Pro Beuchat, analyst PC interface) was used to record diving patterns. No circulating bubbles were detected in the right heart cavities (2D echocardiography) or in the pulmonary artery (continuous Doppler). However, this study had some limits: only 10 subjects were studied and the earliest detection was 3 min after immersion, further studies will thus be required. PMID:9444062

This training unit on protective breathingapparatus is part of a 17-unit course package written to aid instructors in the development, teaching, and evaluation of fire fighters in the Wisconsin Fire Service Certification Series. The purpose stated for the 10-hour unit is to enable the fire fighter to perform routine fire fighting and rescue…

... SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-60... following devices: (a) Two pressure-demand, open circuit, self-contained breathingapparatus, approved by..., subpart 160.011, of this chapter may continue in use as required equipment if it was part of the...

An experimental apparatus designed to study firefighter safety equipment exposed to a thermal environment was developed. The apparatus consisted of an elevated temperature flow loop with the ability to heat the air stream up to 200°C. The thermal and flow conditions at the test section were characterized using thermocouples and bi-directional probes. The safety equipment examined in this study was a self-contained breathingapparatus (SCBA), including a facepiece and an air cylinder. The SCBA facepiece was placed on a mannequin headform and coupled to a breathing simulator that was programmed with a prescribed breathing pattern. The entire SCBA assembly was placed in the test section of the flow loop for these thermal exposure experiments. Three air stream temperatures, 100°C, 150°C, and 200°C, were used with the average air speed at the test section set at 1.4m/s and thermal exposure durations up to 1200 s. Measurements were made using type-K bare-bead thermocouples located in the mannequin's mouth and on the outer surface of the SCBA cylinder. The experimental results indicated that increasing the thermal exposure severity and duration increased the breathing air temperatures supplied by the SCBA. Temperatures of breathing air from the SCBA cylinder in excess of 60°C were observed over the course of the thermal exposure conditions used in most of the experiments. A mathematical model for transient heat transfer was developed to complement the thermal exposure experimental study. The model took into consideration forced convective heat transfer, quasi-steady heat conduction through the composite layers of the SCBA cylinder wall, the breathing pattern and action of the breathing simulator, and predicted air temperatures from the thermally exposed SCBA cylinder and temperatures at the outer surface of the SCBA cylinder. Model predictions agreed reasonably well with the experimental measurements. PMID:25681021

Hydrodynamic coefficients or hydrodynamic derivatives of autonomous underwater vehicles (AUVs) play an important role in their development and maneuverability. The most popular way of estimating their coefficients is to implement captive model tests such as straight line tests and planar motion mechanism (PMM) tests in the towing tanks. This paper aims to develop an apparatus based on planar experiments of water tunnel in order to estimate hydrodynamic derivatives due to AUVs' acceleration and velocity. The capability of implementing straight line tests and PMM ones using mechanical oscillators located in the downstream flow of the model is considered in the design procedure of the system. The hydrodynamic derivatives that resulted from the acceleration and velocity of the AUV model were estimated using the apparatus that we developed. Static and dynamics test results were compared for the similar derivatives. The findings showed that the system provided the basis for conducting static tests, i.e., straight-line and dynamic tests that included pure pitch and pure heave. By conducting such tests in a water tunnel, we were able to eliminate errors related to the time limitation of the tests and the effects of surface waves in the towing tank on AUVs with applications in the deep sea.

Hydrodynamic coefficients or hydrodynamic derivatives of autonomous underwater vehicles (AUVs) play an important role in their development and maneuverability. The most popular way of estimating their coefficients is to implement captive model tests such as straight line tests and planar motion mechanism (PMM) tests in the towing tanks. This paper aims to develop an apparatus based on planar experiments of water tunnel in order to estimate hydrodynamic derivatives due to AUVs' acceleration and velocity. The capability of implementing straight line tests and PMM ones using mechanical oscillators located in the downstream flow of the model is considered in the design procedure of the system. The hydrodynamic derivatives that resulted from the acceleration and velocity of the AUV model were estimated using the apparatus that we developed. Static and dynamics test results were compared for the similar derivatives. The findings showed that the system provided the basis for conducting static tests, i.e., straight-line and dynamic tests that included pure pitch and pure heave. By conducting such tests in a water tunnel, we were able to eliminate errors related to the time limitation of the tests and the effects of surface waves in the towing tank on AUVs with applications in the deep sea. PMID:27370496

The ability to directly measure velocity fields in a fluid environment is necessary to provide empirical data for studies in fields as diverse as oceanography, ecology, biology, and fluid mechanics. Field measurements introduce practical challenges such as environmental conditions, animal availability, and the need for field-compatible measurement techniques. To avoid these challenges, scientists typically use controlled laboratory environments to study animal-fluid interactions. However, it is reasonable to question whether one can extrapolate natural behavior (i.e., that which occurs in the field) from laboratory measurements. Therefore, in situ quantitative flow measurements are needed to accurately describe animal swimming in their natural environment. We designed a self-contained, portable device that operates independent of any connection to the surface, and can provide quantitative measurements of the flow field surrounding an animal. This apparatus, a self-contained underwater velocimetry apparatus (SCUVA), can be operated by a single scuba diver in depths up to 40 m. Due to the added complexity inherent of field conditions, additional considerations and preparation are required when compared to laboratory measurements. These considerations include, but are not limited to, operator motion, predicting position of swimming targets, available natural suspended particulate, and orientation of SCUVA relative to the flow of interest. The following protocol is intended to address these common field challenges and to maximize measurement success. PMID:22064442

Pulmonary oedema has been described in swimmers and self-contained underwaterbreathingapparatus (Scuba) divers. This study reports three cases of haemoptysis secondary to alveolar haemorrhage in breath-hold divers. Contributory factors, such as haemodynamic modifications secondary to immersion, cold exposure, exercise and exposure to an increase in ambient pressure, could explain this type of accident. Furthermore, these divers had taken aspirin, which may have aggravated the bleeding. PMID:10232449

Dysbaric accidents are usually referred to compressed air-supplied diving. Nonetheless, some cases of decompression illness are known to have occurred among breath-hold (BH) divers also, and they are reported in the medical literature. A male BH diver (57 years old), underwater fishing champion, presented neurological disorders as dizziness, sensory numbness, blurred vision, and left frontoparietal pain after many dives to a 30–35 meters sea water depth with short surface intervals. Symptoms spontaneously regressed and the patient came back home. The following morning, pain and neurological impairment occurred again and the diver went by himself to the hospital where he had a generalized tonic-clonic seizure and lost consciousness. A magnetic resonance imaging of the brain disclofsed a cortical T1-weighted hypointense area in the temporal region corresponding to infarction with partial hemorrhage. An early hyperbaric oxygen therapy led to prompt resolution of neurological findings. All clinical and imaging characteristics were referable to the Taravana diving syndrome, induced by repetitive prolonged deep BH dives. The reappearance of neurological signs after an uncommon 21-hour symptom-free interval may suggest an atypical case of Taravana syndrome. PMID:23970902

Dysbaric accidents are usually referred to compressed air-supplied diving. Nonetheless, some cases of decompression illness are known to have occurred among breath-hold (BH) divers also, and they are reported in the medical literature. A male BH diver (57 years old), underwater fishing champion, presented neurological disorders as dizziness, sensory numbness, blurred vision, and left frontoparietal pain after many dives to a 30-35 meters sea water depth with short surface intervals. Symptoms spontaneously regressed and the patient came back home. The following morning, pain and neurological impairment occurred again and the diver went by himself to the hospital where he had a generalized tonic-clonic seizure and lost consciousness. A magnetic resonance imaging of the brain disclofsed a cortical T1-weighted hypointense area in the temporal region corresponding to infarction with partial hemorrhage. An early hyperbaric oxygen therapy led to prompt resolution of neurological findings. All clinical and imaging characteristics were referable to the Taravana diving syndrome, induced by repetitive prolonged deep BH dives. The reappearance of neurological signs after an uncommon 21-hour symptom-free interval may suggest an atypical case of Taravana syndrome. PMID:23970902

An analytical model of the flow across a resistive flow path such as an orifice or pipe was applied to predict the inward leakage in the facepiece of a self-contained breathingapparatus (SCBA) during a steady below-ambient facepiece pressure. The model was used to estimate leakage rates with respect to the size of the leak and for below-ambient (negative) pressure conditions reflective of measured occurrences. Results of the model were also used to make quantitative estimates of the protection level of the respirator. Experiments were designed to induce a continuous below-ambient pressure inside the facepiece of a pressure-demand SCBA mounted on a headform. Negative facepiece pressure measured in the presence of a leak correlated with the measured particle concentration ratio. Results show that the analytical model generated reasonable estimates of leakage rates during conditions of negative pressure inside the facepiece. Thus, the analytical model performed well for constant flow conditions, demonstrating the capability to predict a momentary compromise in respirator protection during momentary negative facepiece pressure conditions. PMID:21667373

A semiclosed-loop rebreathing system is discussed for use in a hostile environment. A packed bed regenerative heat exchanger providing two distinct temperature humidity zones of breathing gas with one zone providing cool, relatively dry air and the second zone providing hot, moist air is described.

We describe the development and application of a Self-Contained Underwater Velocimetry Apparatus (SCUVA), which enables a single SCUBA diver to make DPIV measurements of animal-fluid interactions in the field. The device is used to study Aurelia labiata swimming in the coastal waters of Long Beach, California. SCUVA measurements of animals over a range of sizes are used to directly quantify the kinetic energy in the flow field induced by the swimming motions of individual medusae and are compared with existing theoretical models. The method provides details regarding the temporal evolution of the energetics during the swimming cycle and their scaling with bell diameter. These types of measurements will allow for the determination of propulsive efficiency, which can be used to compare various methods of biological propulsion.

Method and apparatus whereby an anode may be mounted on a subsea propulsion vehicle, transported to a selected portion of a platform substructure and then remotely and operatively connected to the substructure as by explosively-actuated bolts.

A template for spacing a submarine structure such as an anchor block or a guide base for a second underwater well alongside an existing underwater well comprises a beam attached at one end, by means of a hinge, to a lowering guide which can be threaded over and be lowered along two guide wires of the first well, and at the other end by a remote-controlled release mechanism to the submarine structure such as the anchor block itself or a guide base for a second well. The beam, with such a submarine structure attached, is lowered down the guide wires while held in a vertical configuration, and is then swung into a generally horizontal configuration at the sea bed.

Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwaterbreathingapparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue. PMID:25713701

Being able to dive and breatheunderwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

In June 1981, the EFCOM SC-100M/120M/125M wireless communications system was evaluated in conjunction with the AGA DIVATOR 324 Full-Face Mask by the Navy Experimental Diving Unit. The purpose was to determine the systems suitability for U.S. Navy use with open-circuit Self-Contained UnderwaterBreathingApparatus (SCUBA). The EFCOM system was evaluated for intelligibility, reliability and human engineering.

In portable breathingapparatus applications at 1 atm, potassium superoxide (KO2) has exhibited low-utilization efficiency of the available oxygen (O2) and diminished carbon dioxide-(CO2) scrubbing capacity caused by the formation of a fused, hydrated-hydroxide/carbonate product coating on the superoxide granules. In earlier work, it was discovered that granules fabricated from an intimate mixture of KO2 and calcium superoxide, Ca(O2)2, did not exhibit formation of a fused product coating and the utilization efficiency with respect to both O2 release and CO2 absorption was superior to KO2 granules when both types of granules were reacted with humidified CO2 under identified conditions. In the work described here, single pellets of KO2, KO2/Ca(O2), mixtures and commercially available KO2 tables and granules were reacted with a flow of humidified CO2 in helium at 1- and 10-atm total pressure and at an initial temperature of 40 C. In the 1-atm flow tests, the reaction rates and utilization efficiency of the KO2/Ca(O2)2 pellets were markedly superior to the KO2 pellets, tablets, and granules when the samples were reacted under identical conditions. However, at 10 atm, the rates of O2 release and CO2 absorption, as well as the utilization efficiencies of all the superoxide samples, were one-third to one-eighth of the values observed at 1 atm. The decrease in reaction performance at 10 atm compared to that at 1 atm has been attributed principally to the lower bulk diffusivity of the CO2 and H2O reactants in helium at the higher pressure and secondarily to the moderation of the reaction temperature caused by the higher heat capacity of the 10-atm helium.

The performance of escape type breathingapparatus was evaluated for weight, comfort, ease of use, and protection factor (calculated from facepiece leakage). All of the devices tested provided a self-contained air supply of 5- to 15-min duration. Five of them have the provision to connect an air line but allow the use of the self-contained supply for safe egress. The air supply was stored in cylinders, tubing, or disposable containers. Respiratory inlet coverings were half masks, full facepieces, hoods, and mouthpieces. An estimate is given for the ease of quick donning. Recommendations for conditions of use of the equipment are given. 8 refs., 10 figs., 3 tabs.

Self-contained, waterproof, water-submersible, remote-controlled apparatus is described for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer [plus minus]45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer [plus minus]10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

This invention is comprised of a self-contained, waterproof, water-submersible, remote-controlled apparatus provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer {plus_minus} 45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer {plus_minus} 10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

Self-contained, waterproof, water-submersible, remote-controlled apparatus is provided for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer .+-.45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer .+-.10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

According to international guidelines, fitness to dive is generally assessed using a bicycle stress test (BST) in air. To date, there is no study explicitly addressing the question whether the results of a BST in air really predict performance status under water. Therefore, the aim of the present study was twofold: first, to design an experimental setting allowing the examination of physical performance status under water, and second, to examine whether there is an association of response to exercise in air compared to exercise under water using self contained underwaterbreathingapparatus (SCUBA). We constructed and evaluated a measurement technique for a bicycle ergometry and for gas analysis under water. Part of the work was the development of a new valve system which allowed to collect the exhaled air in total and to transport it to the spirometer next to the pool. Twenty-eight healthy male divers underwent a BST. Compared to a given workload in air, gross capacity decreased significantly by about 50% underwater. High performance in air was associated with a high performance underwater. The examinations were carried out without any complications. In conclusion, our experimental setting allowed the safe and reliable examination of physical performance status under water. First results indicate that the results of a BST in air correlate well with the cardio-circulatory performance status underwater. A subsequent study with a larger sample size will enable us to more precisely model this correlation. PMID:16602256

Breathing-metabolic simulator was developed to be used for evaluation of life support equipment. Apparatus simulates human breathing rate and controls temperature and humidity of exhaled air as well as its chemical composition. All functions are designed to correspond to various degrees of human response.

A procedure was developed and tested for recharging Self-Contained BreathingApparatus (SCBA) cylinders in an atmosphere contaminated with chemical agent simulant at concentrations which would produce casualties if actual agent were used. With the exception of a rack for storing the cylinders before and after recharging, all items used are currently available commercially or through off-the-shelf DOD supply sources. Cylinders were successfully recharged without contamination in the presence of chemical agent simulant in the compressor area as well as in the cylinder filling area. Inexperienced personnel easily learned and successfully followed the recharging procedures even though they were burdened by protective clothing and equipment. Chemical agents, SCBA, Firefighting, Self-contained breathingapparatus.

The results of underwater visual fish censuses (UVC) could be affected by fish changing their behavior in response to the snorkeler or diver conducting the survey. We used an underwater video camera to assess how fish abundance, family richness, and community composition were affected by the presence of snorkelers (n = 12) and self-contained underwaterbreathingapparatus (SCUBA) divers (n = 6) on a coral reef in Thailand. The total number of families, abundance of some fish families, and overall species composition showed significant differences before and during snorkeling disturbances. We did not detect significant and consistent changes to these parameters in the presence of a SCUBA diver; however, this could be a result of lower statistical power. We suggest that the use of a stationary video camera may help cross-check data that is collected through UVC to assess the true family composition and document the presence of rare and easily disturbed species. PMID:19353295

During fire emergencies, firefighters wear personal protective devices (PC) and a self-contained breathingapparatus (S.C.B.A.) to be protected from injuries. The purpose of this study was to investigate the differences of aerobic level in 197 firefighters (age: 34±7 yr; BMI: 24.4±2.3 kg.m-2), evaluated by a Queen's College Step field Test (QCST), performed with and without fire protective garments, and to analyze the differences among age groups (<25 yr; 26-30 yr, 31-35 yr, 36-40 yr and >40 yr). Variance analysis was applied to assess differences (p < 0.05) between tests and age groups observed in absolute and weight-related values, while a correlation was examined between QCST with and without PC+S.C.B.A. The results have shown that a 13% of firefighters failed to complete the test with PC+S.C.B.A. and significant differences between QCST performed with and without PC+S.C.B.A. in absolute (F(1,169) = 42.6, p < 0.0001) and weight-related (F(1,169) = 339.9, p < 0.0001) terms. A better correlation has been found in L•min-1 (r=0.67) than in ml•kg-1•min-1 (r=0.54). Moreover, we found significant differences among age groups both in absolute and weight-related values. The assessment of maximum oxygen uptake of firefighters in absolute term can be a useful tool to evaluate the firefighters' cardiovascular strain. PMID:25764201

The first underwater panoramic images were added to Google Maps™, the company announced on 25 September. This first “underwater Street View collection,” launched in partnership with the Caitlin Seaview Survey, provides people with the opportunity to “become the next virtual Jacques Cousteau.” For more information, see: maps.google.com/ocean.

System, based on open-loop demand-type compressed air concept, is lighter and less bulky than former systems, yet still provides thirty minutes of air supply. Comfort, visibility, donning time, and breathing resistance have been improved. Apparatus is simple to recharge and maintain and is comparable in cost to previously available systems.

A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

Light beams in wavy unclear water, also called underwater rays, and caustic networks of light formed at the bottom of shallow water are two faces of a single phenomenon. Derivation of the caustic using only simple geometry, Snell's law and simple derivatives accounts for observations such as the existence of the caustic network on vertical walls,…

... tube) in place. The breath may have an ammonia-like odor (also described as urine-like or " ... kidney failure (can cause breath to smell like ammonia ) Diabetes (fruity or sweet chemical smell associated with ...

... re not getting enough air. Sometimes mild breathing problems are from a stuffy nose or hard exercise. ... emphysema or pneumonia cause breathing difficulties. So can problems with your trachea or bronchi, which are part ...

It is well underwater established that sound waves, compared to electromagnetic waves, propagate long distances in the ocean. Hence, in the ocean as opposed to air or a vacuum, one uses sound navigation and ranging (SONAR) instead navigation and ranging (SONAR) of radar, acoustic communication instead of radio, and acoustic imaging and tomography instead of microwave or optical imaging or X-ray tomography. Underwater acoustics is the science of sound in water (most commonly in the ocean) and encompasses not only the study of sound propagation, but also the masking of sound signals by interfering phenomenon and signal processing for extracting these signals from interference. This chapter we will present the basics physics of ocean acoustics and then discuss applications.

Because of the rising incidence of respiratory injury to firefighters, local governments expressed the need for improved breathingapparatus. A review of the NASA firefighters breathing system program, including concept definition, design, development, regulatory agency approval, in-house testing, and program conclusion is presented.

Four patients with severe chronic obstructive lung disease and recent respiratory failure are described in whom two distinct simultaneous respiratory rhythms were identified, one at 8 to 13 breaths per minute and the other at 39 to 65 per minute. Magnetometer measurements of thoracoabdominal motion together with simultaneous electromyograms of multiple inspiratory muscles suggested that both rhythms were the result of coordinated action of several inspiratory muscles. We suggest that this phenomenon, which we have called dirhythmic breathing, results from the conflicting influence upon respiratory centers and motoneurons of two or more stimuli, some favoring rapid shallow breaths and others slow deep breaths. PMID:7449504

When you're short of breath, it's hard or uncomfortable for you to take in the oxygen your body needs. You may feel as if you're ... stuffy nose or hard exercise. But shortness of breath can also be a sign of a serious ...

A powerful new tool for the analysis and design of underwaterbreathing gas systems is being developed. A versatile computer simulator is described which makes possible the modular ''construction'' of any conceivable breathing gas system from computer memory-resident components. The analysis of a typical breathing gas system is demonstrated using this simulation technique, and the effects of system modifications on performance of the breathing system are shown. This modeling technique will ultimately serve as the foundation for a proposed breathing system simulator under development by the Navy. The marriage of this computer modeling technique with an interactive graphics system will provide the designer with an efficient, cost-effective tool for the development of new and improved diving systems.

... 42 Public Health 1 2011-10-01 2011-10-01 false Service time test; closed-circuit apparatus. 84.96...-Contained BreathingApparatus § 84.96 Service time test; closed-circuit apparatus. (a) The closed-circuit apparatus will be classified according to the length of time it supplies adequate breathing gas to...

... 42 Public Health 1 2011-10-01 2011-10-01 false Service time test; open-circuit apparatus. 84.95...-Contained BreathingApparatus § 84.95 Service time test; open-circuit apparatus. (a) Service time will be measured with a breathing machine as described in § 84.88. (b) The open-circuit apparatus will...

... 42 Public Health 1 2010-10-01 2010-10-01 false Service time test; closed-circuit apparatus. 84.96...-Contained BreathingApparatus § 84.96 Service time test; closed-circuit apparatus. (a) The closed-circuit apparatus will be classified according to the length of time it supplies adequate breathing gas to...

... 42 Public Health 1 2010-10-01 2010-10-01 false Service time test; open-circuit apparatus. 84.95...-Contained BreathingApparatus § 84.95 Service time test; open-circuit apparatus. (a) Service time will be measured with a breathing machine as described in § 84.88. (b) The open-circuit apparatus will...

... mouth and between your teeth produce the bad odor. Other problems in your mouth, such as gum ... and medicines are associated with a specific breath odor. Having good dental habits, like brushing and flossing ...

... hygiene leads to bad breath because when food particles are left in your mouth, they can rot ... Flossing once a day helps get rid of particles wedged between your teeth. Also, visit your dentist ...

The lung sounds are best heard with a stethoscope. This is called auscultation. Normal lung sounds occur ... the bottom of the rib cage. Using a stethoscope, the doctor may hear normal breathing sounds, decreased ...

... gasoline vapor at room temperature (24-30 °C./75-85 °F.) for a continuous period of twice the rated time of the apparatus (except for apparatus for escape only where the test period shall be the rated time of the apparatus). (b) The bag will be operated during this test by a breathing machine with...

The University of Southern California's Catalina Marine Science Center (CMSC) has announced plans to build an underwater marine research laboratory near Santa Catalina Island off the California coast. The project, which will take 2 years to build, will be sponsored by the National Oceanic and Atmospheric Administration (NOAA). The laboratory will be similar in concept to the U.S. Navy Sea Lab III, which was canceled some time ago.The project's purpose is to give divers access to a laboratory without having to surface. The project leader, Andrew Pilmanis, of the University of Southern California, stated recently (Industrial Research and Development, July 1983): “By the nature of the work, scientists require a lot of bottom time, and to do it by scuba isn't practical…. The only way to do that is with saturation diving. Once the diver is saturated with inert gas, whether the individual stays a few days or for months, only one decompression is required.” Divers will typically stay in the laboratory for 7-10 days. The laboratory will initially be placed at a depth of 20 m, later to be refloated and located at depths to 37 m.

If you have breathing problems and you: Are short of breath most of the time Get short of breath when you walk 150 ... or less Have been in the hospital for breathing problems recently Use oxygen at home, even if ...

... classified according to the length of time it supplies air or oxygen to the breathing machine. (c) The... 42 Public Health 1 2012-10-01 2012-10-01 false Service time test; open-circuit apparatus. 84.95...-Contained BreathingApparatus § 84.95 Service time test; open-circuit apparatus. (a) Service time will...

... classified according to the length of time it supplies air or oxygen to the breathing machine. (c) The... 42 Public Health 1 2013-10-01 2013-10-01 false Service time test; open-circuit apparatus. 84.95...-Contained BreathingApparatus § 84.95 Service time test; open-circuit apparatus. (a) Service time will...

In this article, the author describes a project wherein students created colorful underwater sea creatures. This project began with a discussion about underwater sea creatures and how they live. The first step was making the multi-colored tissue paper that would become sea creatures and seaweed. Once students had the shapes of their sea creatures…

In this article, the author describes an underwater scene composition for elementary-education majors. This project deals with watercolor with crayon or oil-pastel resist (medium); the beauty of nature represented by fish in the underwater scene (theme); texture and pattern (design elements); drawing simple forms (drawing skill); and composition…

... Body & lifestyle changes > Shortness of breath Shortness of breath E-mail to a friend Please fill in ... oxygen your baby gets. Causes of shortness of breath during pregnancy Early pregnancy In the first few ...

... To a limited degree, you can change your breathing rate, such as by breathing faster or holding your ... oxygen levels in your blood and change your breathing rate as needed. Sensors in the airways detect lung ...

Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

... less than a minute before a child regains consciousness and resumes breathing normally. Breath-holding spells can ... spells cause kids to stop breathing and lose consciousness for up to a minute. In the most ...

Discusses differences between smell and taste, comparing these senses in organisms in aquatic and terrestrial environments. Describes the chemical environment underwater and in air, differences in chemoreceptors to receive stimuli, and the organs, brain, and behavior involved in chemoreception. (CS)

The Atlantic Undersea Test and Evaluation Center (AUTEC) is a U.S. Navy test range located on Andros Island, Bahamas, and a Division of the Naval Undersea Warfare Center (NUWC), Newport, RI. The Headquarters of AUTEC is located at a facility in West Palm Beach, FL. AUTEC's primary mission is to provide the U.S. Navy with a deep-water test and evaluation facility for making underwater acoustic measurements, testing and calibrating sonars, and providing accurate underwater, surface, and in-air tracking data on surface ships, submarines, aircraft, and weapon systems. Many of these programs are in support of Antisubmarine Warfare (ASW), undersea research and development programs, and Fleet assessment and operational readiness trials. Most tests conducted at AUTEC require precise underwater tracking (plus or minus 3 yards) of multiple acoustic signals emitted with the correct waveshape and repetition criteria from either a surface craft or underwater vehicle.

Apparatus for generating a substantially oscillation-free seismic signal for use in underwater petroleum exploration, including a bag with walls that are flexible but substantially inelastic, and a pressured gas supply for rapidly expanding the bag to its fully expanded condition is described. The inelasticity of the bag permits the application of high pressure gas to rapidly expand it to full size, without requiring a venting mechanism to decrease the pressure as the bag approaches a predetermined size to avoid breaking of the bag.

A sperm whale (Physeter macrocephalus) was observed at the surface with above- and underwater video and synchronized underwater sound recordings. During seven instances the whale ventilated its lungs while clicking. From this observation it is inferred that click production is achieved by pressurizing air in the right nasal passage, pneumatically disconnected from the lungs and the left nasal passage, and that air flows anterior through the phonic lips into the distal air sac. The capability of breathing and clicking at the same time is unique among studied odontocetes and relates to the extreme asymmetry of the sperm whale sound-producing forehead.

Describes three pieces of scientific apparatus and their demonstrational use: a high temperature apparatus for positron annihilation studies, a digitally synthesized classroom variable star, and a demonstration of plasma laser-beam focusing using paint stripper flames. (GA)

4-H clubs can build and program underwater robots from raw materials. An annotated resource list for engaging youth in building underwater remotely operated vehicles (ROVs) is provided. This article is a companion piece to the Research in Brief article "Building Teen Futures with Underwater Robotics" in this issue of the "Journal of…

Flexible underwater lift devices ('lift bags') are used in underwater operations to provide buoyancy to submerged objects. Commercially available designs are heavy, bulky, and awkward to handle, and thus are limited in size and useful lifting capacity. An underwater lift device having less than 20 percent of the bulk and less than 10 percent of the weight of commercially available models was developed. The design features a dual membrane envelope, a nearly homogeneous envelope membrane stress distribution, and a minimum surface-to-volume ratio. A proof-of-concept model of 50 kg capacity was built and tested. Originally designed to provide buoyancy to mock-ups submerged in NASA's weightlessness simulators, the device may have application to water-landed spacecraft which must deploy flotation upon impact, and where launch weight and volume penalties are significant. The device may also be useful for the automated recovery of ocean floor probes or in marine salvage applications.

Human underwaterbreath-hold diving is a fascinating example of applied environmental physiology. In combination with swimming, it is one of the most popular forms of summer outdoor physical activities. It is performed by a variety of individuals ranging from elite breath-hold divers, underwater hockey and rugby players, synchronized and sprint swimmers, spear fishermen, sponge harvesters and up to recreational swimmers. Very few data currently exist concerning the influence of regular breath holding on possible health risks such as cerebrovascular, cardiovascular and respiratory diseases. A literature search of the PubMed electronic search engine using keywords 'breath-hold diving' and 'apnoea diving' was performed. This review focuses on recent advances in knowledge regarding possibly harmful physiological changes and/or potential health risks associated with breath-hold diving. Available evidence indicates that deep breath-hold dives can be very dangerous and can cause serious acute health problems such a collapse of the lungs, barotrauma at descent and ascent, pulmonary oedema and alveolar haemorrhage, cardiac arrest, blackouts, nitrogen narcosis, decompression sickness and death. Moreover, even shallow apnoea dives, which are far more frequent, can present a significant health risk. The state of affairs is disturbing as athletes, as well as recreational individuals, practice voluntary apnoea on a regular basis. Long-term health risks of frequent maximal breath holds are at present unknown, but should be addressed in future research. Clearly, further studies are needed to better understand the mechanisms related to the possible development or worsening of different clinical disorders in recreational or competitive breath holding and to determine the potential changes in training/competition regimens in order to prevent these adverse events. PMID:22574634

... confronted Breath holding spells are more common in children with: Genetic conditions, such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells (parents ...

Breath malodour is a condition that has health and social implications. The origin of breath malodour problems are related to both systemic and oral conditions. The advice of dental professionals for treatment of this condition occurs with regularity since 90% of breath odor problems emanate from the oral cavity. This paper provides a comprehensive review of the etiology of breath odor, its prevalence, diagnosis, and treatment strategies for the condition. PMID:12167916

Background Laparoscopic and robotic surgeries have become popular, and this popularity is increasing. However, the environment in which such surgeries are performed is rarely discussed. Similar to arthrosurgery performed in water, artificial ascites could be a new environment for laparoscopic surgery. This study was performed to determine whether robotic surgery is applicable to complicated suturing underwater. Material and methods A da Vinci Surgical System S was used. A weighted fabric sheet was placed at the bottom of a tank. Identical sets were made for each environment: One tank was dry, and the other was filled with water. The suturing task involved placement of a running silk suture around the perimeter of a small circle. The task was performed eight times in each environment. The task time and integrity score were determined. The integrity score was calculated by evaluating accuracy, tightness, thread damage, and uniformity; each factor was evaluated using a five-point scale. Results Although statistically significant differences were not shown in either task time or integrity score between the underwater and air environments, robotic suturing underwater is not inferior to performance in air. Conclusions The feasibility of robotic suturing underwater was confirmed under the herein-described experimental conditions. PMID:26853072

important concern is a suite of products from chemical reactions among oxidizing compounds with biological chemicals such as amines, thiols and carbonyls. SAMAP Meeting We (Armin and Joachim) attended the 2011 SAMAP conference in Taranto, Italy (10-14 October), which occurred just a few weeks after the IABR meeting in Parma, Italy (11-15 September 2011). It was held at the Officers' Club of the Taranto Naval Base under the patronage of the Italian navy; the local host was Lucio Ricciardi of the University of Insubria, Varese, Italy. At the 2011 SAMAP meeting, the theme was air-independent propulsion (AIP), meaning the capability of recharging the main batteries of the submarine without the need to surface. Only a few navies (e.g. US, UK, France, Russia, China) have historically had this capability using nuclear-powered submarines that can function underwater for extended periods of time (months). Most navies operate submarines with conventional diesel-electric propulsion, wherein diesel-powered generators charge battery banks which then drive an electric motor connected to the propeller. The batteries are charged while the boat is on the surface or during snorkelling, when the boat is submerged a few meters below the surface and a snorkel tube is extended to the surface. The period between battery charges can vary from several hours to one or two days depending on the power requirements and the nature of the mission. The process is necessary for breathing air revitalization (flushing out accumulated contaminants) and for the operation of the diesel engines. However, during this period the submarine is vulnerable to detection. Since the 1940s there have been various attempts to develop a power generation system that is independent of external air (AIP). To this end hydrogen peroxide was initially used and later liquid oxygen (LOX). Currently, most AIP submarines use fuel cell technology (LOX and hydrogen) to supplement the conventional diesel-electric system in order to

The development of a breathing metabolic simulator (BMS) is reported. This BMS simulates all of the breathing and metabolic parameters required for complete evaluation and test of life support and resuscitation equipment. It is also useful for calibrating and validating mechanical and gaseous pulmonary function test procedures. Breathing rate, breathing depth, breath velocity contour, oxygen uptake, and carbon dioxide release are all variable over wide ranges simulating conditions from sleep to hard work with respiratory exchange ratios covering the range from hypoventilation. In addition, all of these parameters are remotely controllable to facilitate use of the device in hostile or remote environments. The exhaled breath is also maintained at body temperature and a high humidity. The simulation is accurate to the extent of having a variable functional residual capacity independent of other parameters.

The general topic of this review is protein-based underwater adhesives produced by aquatic organisms. The focus is on mechanisms of interfacial adhesion to native surfaces and controlled underwater solidification of natural water-borne adhesives. Four genera that exemplify the broad range of function, general mechanistic features, and unique adaptations are discussed in detail: blue mussels, acorn barnacles, sandcastle worms, and freshwater caddisfly larva. Aquatic surfaces in nature are charged and in equilibrium with their environment, populated by an electrical double layer of ions as well as adsorbed natural polyelectrolytes and microbial biofilms. Surface adsorption of underwater bioadhesives likely occurs by exchange of surface bound ligands by amino acid sidechains, driven primarily by relative affinities and effective concentrations of polymeric functional groups. Most aquatic organisms exploit modified amino acid sidechains, in particular phosphorylated serines and hydroxylated tyrosines (dopa), with high-surface affinity that form coordinative surface complexes. After delivery to the surfaces as a fluid, permanent natural adhesives solidify to bear sustained loads. Mussel plaques are assembled in a manner superficially reminiscent of in vitro layer-by-layer strategies, with sequentially delivered layers associated through Fe(dopa)3 coordination bonds. The adhesives of sandcastle worms, caddisfly larva, and barnacles may be delivered in a form somewhat similar to in vitro complex coacervation. Marine adhesives are secreted, or excreted, into seawater that has a significantly higher pH and ionic strength than the internal environment. Empirical evidence suggests these environment triggers could provide minimalistic, fail-safe timing mechanisms to prevent premature solidification (insolubilization) of the glue within the secretory system, yet allow rapid solidification after secretion. Underwater bioadhesives are further strengthened by secondary covalent

Underwater welding, cutting and inspection of offshore, inland waterway and port facilities are becoming a requirement for both military and industrial communities, as maintenance and repair costs continue to escalate, and as many of the facilities are in operation well beyond their intended design life. In nuclear applications, underwater welding, cutting and inspection for repair and modification of irradiated nuclear power plant components are also a requirement. This article summarizes recent developments in this emerging underwater technology.

The conventional method used to detect an underwater target is by sending and receiving some form of acoustic energy. But the acoustic systems have limitations in the range resolution and accuracy; while, the potential benefits of a laserbased underwater target detection include high directionality, high response, and high range accuracy. Lasers operating in the blue-green region of the light spectrum(420 : 570nm)have a several applications in the area of detection and ranging of submersible targets due to minimum attenuation through water ( less than 0.1 m-1) and maximum laser reflection from estimated target (like mines or submarines) to provide a long range of detection. In this paper laser attenuation in water was measured experimentally by new simple method by using high resolution spectrometer. The laser echoes from different targets (metal, plastic, wood, and rubber) were detected using high resolution CCD camera; the position of detection camera was optimized to provide a high reflection laser from target and low backscattering noise from the water medium, digital image processing techniques were applied to detect and discriminate the echoes from the metal target and subtract the echoes from other objects. Extraction the image of target from the scattering noise is done by background subtraction and edge detection techniques. As a conclusion, we present a high response laser imaging system to detect and discriminate small size, like-mine underwater targets.

This invention concerns a sensitive apparatus for detecting and counting neutrons, particularly neutrons liberated in an alpha, neutron reaction. The apparatus includes an improved ionization chamber structure together with an improved combination alpha-particle source and holder for the material under test.

Subsystem was developed which provides twelve waveform controls to breath drive mechanism. Twelve position, magnetically actuated rotary switch is connected to one end of crankshaft drive, such that it makes one complete revolution for each simulated breath. Connections with common wired point are included in modifications made to standard motor speed controller.

Respiratory gas exchange, end-tidal gas tensions, alveolar ventilation, respiratory frequency, cardiac output, and pulse rate were measured in four healthy adult males at rest and during mild and moderate exercise in air at 18-22 C and underwater at 35.0-35.5 C. Immersion was associated with a 10% increase in pulse rate and cardiac output at all levels of exercise. There were no changes in end-tidal CO2 tension or alveolar ventilation. It is concluded that horizontal subjects breathing at eupneic pressures and working against mild and moderate loads in warm water show the same responses to exercise as in air.-

Exposure of divers to intense noise in water is increasing, yet there is no general hearing conservation standard for such exposures. This paper reviews three theories of underwater hearing as well as empirical data in order to identify some requirements that an underwater conservation standard must meet. Among the problems considered are hearing sensitivity in water, the frequency and dynamic ranges of the water-immersed ear, and nonauditory effects of underwater sound. It is concluded that: first, no well developed theoretical basis exists for extrapolating hearing conservation standards for airborne noise to the underwater situation; second, the empirical data on underwater hearing suggest that the frequency range covered by an underwater hearing conservation standard must be broader than is the case in air; third, in order to establish a general hearing conservation standard for underwater noise exposure further research is required on the dynamic range of the ear in water; fourth, underwater noise exposure may involve hazards to other body systems than the ear; and fifth, some exposure conditions may interfere with job performance of divers.

The ionic polymer-metal composite (IPMC) is a soft material based actuator and sensor and has a promising potential in underwater application. This paper describes a hybrid biomimetic underwater vehicle that uses IPMCs as sensors. Propelled by the energy of waves, this underwater vehicle does not need an additional energy source. A physical model based on the hydrodynamics of the vehicle was developed, and simulations were conducted. Using the Poisson-Nernst-Planck system of equations, a physics model for the IPMC sensor was proposed. For this study, experimental apparatus was developed to conduct hydrodynamic experiments for both the underwater vehicle and the IPMC sensors. By comparing the experimental and theoretical results, the speed of the underwater vehicle and the output of the IPMC sensors were well predicted by the theoretical models. A maximum speed of 1.08 × 10(-1) m s(-1) was recorded experimentally at a wave frequency of 1.6 Hz. The peak output voltage of the IPMC sensor was 2.27 × 10(-4) V, recorded at 0.8 Hz. It was found that the speed of the underwater vehicle increased as the wave frequency increased and the IPMC output decreased as the wave frequency increased. Further, the energy harvesting capabilities of the underwater vehicle hosting the IPMCs were tested. A maximum power of 9.50 × 10(-10) W was recorded at 1.6 Hz. PMID:26414228

This report is concerned with the development of an ultra low cost underwater propulsion that can horizontally deploy 500 - 1000 feet of sonobuoy cable at depths between 500 and 1000 feet. A trade-off analysis shows that the best system is based on a gas driven water pulsejet (hydropulse) and that the best source of gas is a reaction between Lithium aluminum hydride (LiAlH4) and seawater. The fuel cost for -15 minutes of operation is about $2.00. A design for the pulsejet engine was then prepared (the drawings are in Appendix C) together with reaction rate measuring equipment. This culminates Phase I of the contract.

We present the first experimental observation of a new hydrodynamic phenomenon, the underwater tornado. Simple measurements show that the tornado forms a vortex of the Rankine type, i.e. the rising gas rotates as a solid body and the liquid rotates with a velocity decreasing hyperbolically with the radius. We obtain the dependence of the tornado radius a on the gas stream value j theoretically: a ∼ j2/5. Processing of a set of experiments yielded the value 0.36 for the exponent in this expression. We also report the initial stages of the theoretical study of this phenomenon.

Describes the Packard's Falling Body Apparatus, invented by John C. Packard, which is essentially an inclined plane combined with a simple and elegant method of measuring the relative time of descent of a steel ball. (JRH)

Presents a technique to produce samples for x-ray diffraction studies on the Tel-X-Ometer 80 x-ray apparatus from readily available crystalline powders and discusses observations of transverse modes of an optical resonator. (SK)

The hearing of turtles is poorly understood compared with the other reptiles. Although the mechanism of transduction of sound into a neural signal via hair cells has been described in detail, the rest of the auditory system is largely a black box. What is known is that turtles have higher hearing thresholds than other reptiles, with best frequencies around 500 Hz. They also have lower underwater hearing thresholds than those in air, owing to resonance of the middle ear cavity. Further studies demonstrated that all families of turtles and tortoises share a common middle ear cavity morphology, with scaling best suited to underwater hearing. This supports an aquatic origin of the group. Because turtles hear best under water, it is important to examine their vulnerability to anthropogenic noise. However, the lack of basic data makes such experiments difficult because only a few species of turtles have published audiograms. There are also almost no behavioral data available (understandable due to training difficulties). Finally, few studies show what kinds of sounds are behaviorally relevant. One notable paper revealed that the Australian snake-necked turtle (Chelodina oblonga) has a vocal repertoire in air, at the interface, and under water. Findings like these suggest that there is more to the turtle aquatic auditory scene than previously thought. PMID:26611091

We have developed a laser vibrometer based on an monolithic single-frequency green laser operating at 532 nm. This wavelength can be particularly useful in the case of underwater vibrometry, especially with regard to the minimum of water absorption for this wavelength range (blue-green window). Using polarizing optics, we proposed a configuration that allows the elimination of parasitic reflections at the air-glass-water boundary. A measurement of heterodyne signals as a mixing result of scattered and reference beams has been performed. The study was conducted in aqueous medium for the scattering waterproof paper and retro-reflective surface. In both configurations we have obtained signals with a relatively high S/N ratio > 20 dB (for scattering surface) and > 31 dB (for retro-reflective tape) with the Resolution Bandwidth RBW 10 kHz for a vibrometer output power of 5 mW and the distance to the moving object 1.2 m (including 0.3 m in air). In our opinion, laser Doppler vibrometry LDV based on high-performance single frequency solid-state lasers with a wavelength range corresponding to the blue-green window allows effective measurement of vibration in the underwater environment.

The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathingapparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

Description of a device for simulation of the human breathing and metabolic parameters required for the evaluation of respiratory diagnostic, monitoring, support and resuscitation equipment. The remotely controlled device allows wide variations in breathing rate and depth, breath velocity contour, oxygen uptake and carbon dioxide release to simulate conditions from sleep to hard work, with respiration exchange ratios ranging from hypoventilation to hyperventilation. It also reduces the cost of prolonged testing when simulation chambers with human subjects require three shifts of crews and standby physicians. Several block diagrams of the device and subsystems are given.

... a high altitude Blood clot in the lung Collapsed lung (pneumothorax) Heart attack Injury to the neck, chest wall, ... cavity with each breath. This can cause a collapsed lung . Bandage the wound with plastic wrap, a plastic ...

... can occur with obstructive sleep apnea, for example. Prolonged apnea means a person has stopped breathing. If ... that requires immediate medical attention and first aid. Prolonged apnea with no heart activity in a person ...

... can lead to shortness of breath include anxiety, panic attacks, anemia and even constipation. The experience of shortness ... are used to treat patients with anxiety or panic attacks. Other commonly used drugs include bronchodilators to widen ...

... deep breath, which usually results in retention of carbon dioxide and not enough oxygen in blood (obesity hypoventilation ... for anemia), and oximetry or blood oxygen or carbon dioxide levels. Your doctor also may obtain a chest ...

So far, there is no evidence that humpback whales are negatively affected by noise emitted from underwater speakers that may one day be used to measure warming in the oceans. A group of independent biologists from Cornell University monitored the behavior of the whales before, during, and after a scaled-down version of the controversial Acoustic Thermometry of Ocean Climate (ATOC) experiment off the coast of Hawaii. In 84 trials from February through March, they “saw no overt response from the whales.” Previous observations of similar sound transmissions at California's Pioneer Seamount, the other site planned for the experiment, also found no sign of disturbance among marine mammals, including elephant seals and several whale species. More observations are needed, however, before the experiment can be deemed safe, the Cornell biologists advised.

Although the method and apparatus of the present invention can be utilized to apply either a uniform or a nonuniform covering of material over many different workpieces, the apparatus (20) is advantageously utilized to apply a thermal barrier covering (64) to an airfoil (22) which is used in a turbine engine. The airfoil is held by a gripper assembly (86) while a spray gun (24) is effective to apply the covering over the airfoil. When a portion of the covering has been applied, a sensor (28) is utilized to detect the thickness of the covering. A control apparatus (32) compares the thickness of the covering of material which has been applied with the desired thickness and is subsequently effective to regulate the operation of the spray gun to adaptively apply a covering of a desired thickness with an accuracy of at least plus or minus 0.0015 inches (1.5 mils) despite unanticipated process variations.

Transformer apparatus is designed for measuring the amount of a paramagnetic substance dissolved or suspended in a diamagnetic liquid. The apparatus consists of a cluster of tubes, some of which are closed and have sealed within the diamagnetic substance without any of the paramagnetic material. The remaining tubes are open to flow of the mix- ture. Primary and secondary conductors are wrapped around the tubes in such a way as to cancel noise components and also to produce a differential signal on the secondaries based upon variations of the content of the paramagnetic material. (AEC)

An apparatus for introducing ionizing radiation into compressed gas insulation systems, such as high-voltage generators or transmission lines to smooth out electrical discontinuities, particularly those caused by foreign particulates that produce high gradients, and to increase the voltage holding capability of the system is described. The apparatus of the invention may also be used to regulate and stabilize the voltage of the system by varying the amount of applied load. A corona discharge device may also be used in conjunction with the invention. (Official Gazette)

Molding apparatus capable of coating multiple elements each molding cycle is described. The apparatus comprises a centrally disposed reservoir penetrated by a plurality of circumferentially arranged and radially extending passageways. These passageways, in turn, communicate with passages in a separable annular member that retains selectively configured molds and mold seating arrangements. Each mold, which is readily removable from its respective seat, is adapted to retain an element therein in spaced relation to the interior of the mold by utilizing element positioning means within the mold seat and the mold so that coating material may flow about the entire outer surface of the element. (AEC)

An apparatus is provided for precisely adjusting the position of an article relative to a beam emerging from a neutron source disposed in a housing. The apparatus includes a support pivotably mounted on a movable base plate and freely suspended therefrom. The support is gravity biased toward the housing and carries an article holder movable in a first direction longitudinally of the axis of said beam and normally urged into engagement against said housing. Means are provided for moving the base plate in two directions to effect movement of the suspended holder in two mutually perpendicular directions, respectively, normal to the axis of the beam.

Underwater wet welding is conducted directly in water with the shielded metal arc (SMA) and flux cored arc (FCA) welding processes. Underwater wet welding has been demonstrated as an acceptable repair technique down to 100 meters (325 ft.) in depth, but wet welds have been attempted on carbon steel structures down to 200 meters (650 ft.). The primary purpose of this interpretive report is to document and evaluate current understanding of metallurgical behavior of underwater wet welds so that new welding consumables can be designed and new welding practices can be developed for fabrication and repair of high strength steel structures at greater depths. First the pyrometallurgical and physical metallurgy behaviors of underwater weldments are discussed. Second, modifications of the welding consumables and processes are suggested to enhance the ability to apply wet welding techniques.

An aerodynamic heated steam generating apparatus is described which consists of: an aerodynamic heat immersion coil steam generator adapted to be located on the leading edge of an airframe of a hypersonic aircraft and being responsive to aerodynamic heating of water by a compression shock airstream to produce steam pressure; an expansion shock air-cooled condensor adapted to be located in the airframe rearward of and operatively coupled to the aerodynamic heat immersion coil steam generator to receive and condense the steam pressure; and an aerodynamic heated steam injector manifold adapted to distribute heated steam into the airstream flowing through an exterior generating channel of an air-breathing, ducted power plant.

Cardiovascular examination of a certain number of candidates for underwater diving raises justifiable questions of aptitude. An indicative list of contraindications has been proposed by the French Federation of Underwater Studies and Sports but a physiopathological basis gives a better understanding of what is involved. During diving, the haemodynamic changes due not only to the exercise but also to cold immersion, hyperoxaemia and decompression impose the absence of any symptomatic cardiac disease. Moreover, the vasoconstriction caused by the cold and hyperoxaemia should incite great caution in both coronary and hypertensive patients. The contraindication related to betablocker therapy is controversial and the debate has not been settled in France. The danger of drowning makes underwater diving hazardous in all pathologies carrying a risk of syncope. Pacemaker patients should be carefully assessed and the depth of diving limited. Finally, the presence of right-to-left intracardiac shunts increases the risk of complications during decompressionand contraindicates underwater diving. Patent foramen ovale is a special case but no special investigation is required for its detection. The cardiologist examining candidates for underwater diving should take all these factors into consideration because, although underwater diving is a sport associated with an increased risk, each year there are more and more people, with differing degrees of aptitude, who wish to practice it. PMID:17181043

The growing need for underwater observation and subsea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, biogeochemical, evolutionary, and ecological changes in the sea, ocean, and lake environments, and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. Models are presented for three kinds of optical wireless communication links: (a) a line-of-sight link, (b) a modulating retroreflector link, and (c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered light it was possible to mitigate this decrease in some cases. It is concluded from the analysis that a high-data-rate underwater optical wireless network is a feasible solution for emerging applications such as UUV-to-UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

Presents four short articles on: a power supply for the measurement of the charge-to-mass ratio of the electron; a modified centripetal force apparatus; a black box electronic unknown for the scientific instruments laboratory; and a simple scaling model for biological systems. (MLH)

There are disclosed several alternate embodiments of wellhead apparatus of the type in which hydraulic fluid may be transmitted to and/or from a subsurface safety valve or other hydraulically operable device within the well through an annular space formed between the production tubing.

The present invention relates to an apparatus for handling a workpiece comprising a vessel that is longitudinally extensible and pressurizable, and a nonextensible and laterally flexible member on the vessel. The member constrains one side of the vessel to be nonextensible, causing the vessel to bend in the direction of the nonextensible member when pressurized.

The present invention relates to an apparatus for handling a workpiece comprising a vessel that is longitudinally extensible and pressurizable, and a nonextensible and laterally flexible member on the vessel. The member constrains one side of the vessel to be nonextensible, causing the vessel to bend in the direction of the nonextensible member when pressurized. 8 figures.

An apparatus and method for exercising whereby the user is supported by various mechanisms in such as way that the user's shoulder area is free to translate and rotate; the user's pelvic area is free to translate and rotate; or in any combination.

Describes some science apparatus: included are a gene kit to demonstrate aspects of population genetics and selection, an electronic thermometer for use in the field of environmental studies, an astrobrella to use in astronomy classes, and crystal display models of different substances for chemistry classes. (GA)

A sensor apparatus and method for detecting an environmental factor is shown that includes an acoustic device that has a characteristic resonant vibrational frequency and mode pattern when exposed to a source of acoustic energy and, futher, when exposed to an environmental factor, produces a different resonant vibrational frequency and/or mode pattern when exposed to the same source of acoustic energy.

We demonstrate a novel miniature optical breathing sensor based on an Agarose infiltrated photonic crystal fiber interferometer. The sensor detects the variation in relative humidity that occurs between inhaled and exhaled breath. The sensor interrogation system can determine the breathing pattern in real time and can also predict the breathing rate and the breathing status during respiration. The sensor is suitable for monitoring patients during a magnetic resonance imaging scan where use of sedatives and anesthetics necessitates breathing monitoring; electronic sensors are not suitable in such an environment and a visual observation of the patient's respiratory efforts is often difficult. PMID:23243581

Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood. PMID:12598679

The linear mechanism for optical-to-acoustic energy conversion is explored for optoacoustic communication from an in-air platform or surface vessel to a submerged vessel such as a submarine or unmanned undersea vehicle. The communication range that can be achieved is addressed. A number of conventional signals used in underwater acoustic telemetry applications are shown to be capable of being generated experimentally through the linear optoacoustic regime conversion process. These results are in agreement with simulation based on current theoretical models. A number of practical issues concerning linear optoacoustic communication are addressed that lead to a formulation of a linear-regime optoacoustic communication scheme. The use of oblique laser beam incidence at the air-water interface to obtain considerable in-air range from the laser source to the in-water receiver is addressed. Also, the effect of oblique incidence on in-water range is examined. Next, the optimum and suboptimum linear optoacoustic sound-generation techniques for selecting the optical wavelength and signaling frequency for optimizing in-water range are addressed and discussed. Optoacoustic communication techniques employing M-ary frequency shift keying and multifrequency shift keying are then compared with regard to communication parameters such as bandwidth, data rate, range coverage, and number of lasers employed. PMID:15989059

Low probability of detection (LPD) communications are conducted at a low received signal-to-noise ratio (SNR) to deter eavesdroppers to sense the presence of the transmitted signal. Successful detection at intended receiver heavily relies on the processing gain achieved by employing the direct-sequence spread-spectrum (DSSS) technique. For scenarios that lack a sufficiently low SNR to maintain LPD, another metric, referred to as low probability of interception (LPI), is of interest to protect the privacy of the transmitted information. If covert communications take place in underwater acoustic (UWA) environments, then additional challenges are present. The time-varying nature of the UWA channel prevents the employment of a long spreading waveform. Furthermore, UWA environments are frequency-selective channels with long memory, which imposes challenges to the design of the spreading waveform. In this paper, a covert UWA communication system that adopts the DSSS technique and a coherent RAKE receiver is investigated. Emphasis is placed on the design of a spreading waveform that not only accounts for the transceiver structure and frequency-selective nature of the UWA channel, but also possesses a superior LPI. The proposed techniques are evaluated using both simulated and SPACE'08 in-water experimental data. PMID:21110585

We review theoretical models to show that contrast reduction at a specific wavelength in the horizontal direction depends directly on the beam attenuation coefficient at that wavelength. If a black target is used, the inherent contrast is always negative unity, so that the visibility of a black target in the horizontal direction depends on a single parameter only. That is not the case for any other target or viewing arrangement. We thus propose the horizontal visibility of a black target to be the standard for underwater visibility. We show that the appropriate attenuation coefficient can readily be measured with existing simple instrumentation. Diver visibility depends on the photopic beam attenuation coefficient, which is the attenuation of the natural light spectrum convolved with the spectral responsivity of the human eye (photopic response function). In practice, it is more common to measure the beam attenuation coefficient at one or more wavelength bands. We show that the relationship: visibility is equal to 4.8 divided by the photopic beam attenuation coefficient; originally derived by Davies-Colley [1], is accurate with an average error of less than 10% in a wide variety of coastal and inland waters and for a wide variety of viewing conditions. We also show that the beam attenuation coefficient measured at 532 nm, or attenuation measured by a WET Labs commercial 20 nm FWHM transmissometer with a peak at 528nm are adequate substitutes for the photopic beam attenuation coefficient, with minor adjustments. PMID:19471421

This report was prepared with the object of developing guidelines for designing underwater connections of branch pipelines to main lines at existing tap valves and with hot taps in diver accessible water depths. The report considers ANSI Classes 600 and 900 branch pipelines of up to twelve inches in diameter that conform to API Specification 5L minimum. Loads due to gravity, buoyancy, intemal and external pressure, thermal expansion, hydrodynamics and random events are considered. External corrosion, temperature, cover, bottom conditions, stability, testing, commissioning, trenching, and pigging are also addressed. A general discussion of these issues is included in the body of the report. Methods of analysis are included in the appendices and in various references. Lotus 123'' spreadsheets that compute the expansion stresses resulting from pressure and temperature at points on a generic piping geometry are presented. A program diskette is included with the report. The report summarizes, and draws from, the results of a survey of the relevant practice and experience of fifteen gas pipeline operating companies. The survey indicates that most existing branch connections do not provide for pigging of the lateral lines, but that there is a growing consensus that cleaning and inspection pigging of lateral lines is desirable or necessary.

A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface.

A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface. 15 figs.

An apparatus whereby relatlvely volatile solvents may be contacted with volatile or non-volatile material without certaln attendant hazards is described. A suitable apparatus for handling relatively volatlle liqulds may be constructed comprising a tank, and a closure covering the tank and adapted to be securely attached to an external suppont. The closure is provided with a rigidly mounted motor-driven agitator. This agitator is connected from the driving motor lnto the lnterlor of the tank through a gland adapted to be cooled witb inert gas thereby eliminating possible hazard due to frictional heat. The closure is arranged so that the tank may be removed from it without materially dlsturbing the closure which, as described, carrles the motor driven agitator and other parts.

A hyperthermia apparatus, suitable for transurethral application, has an energy radiating element comprising a leaky-wave antenna. The leaky wave antenna radiation pattern is characterized by a surface wave which propagates along an aperture formed by openings (small in comparison to a wavelength) in the outer conductor of a transmission line. Appropriate design of the leaky wave antenna produces a uniform, broadside pattern of temperature elevation that uniformly heats all or part of the periurethral tissues.

A method and apparatus for operating a continuous flow blood separation centrifuge are provided. The hematocrit of the entrant whole blood is continuously maintained at an optimum constant value by the addition of plasma to the entrant blood. The hematocrit of the separated red cells is monitored to indicate the degree of separation taking place, thereby providing a basis for regulating the flow through the centrifuge.

An apparatus is described for casting small quantities of uranlum. It consists of a crucible having a hole in the bottom with a mold positioned below. A vertical rcd passes through the hole in the crucible and has at its upper end a piercing head adapted to break the oxide skin encasing a molten uranium body. An air tight cylinder surrounds the crucible and mold, and is arranged to be evacuated.

Sensor technology has matured enough to be used in any type of environment. The appearance of new physical sensors has increased the range of environmental parameters for gathering data. Because of the huge amount of unexploited resources in the ocean environment, there is a need of new research in the field of sensors and sensor networks. This special issue is focused on collecting recent advances on underwater sensors and underwater sensor networks in order to measure, monitor, surveillance of and control of underwater environments. On the one hand, from the sensor node perspective, we will see works related with the deployment of physical sensors, development of sensor nodes and transceivers for sensor nodes, sensor measurement analysis and several issues such as layer 1 and 2 protocols for underwater communication and sensor localization and positioning systems. On the other hand, from the sensor network perspective, we will see several architectures and protocols for underwater environments and analysis concerning sensor network measurements. Both sides will provide us a complete view of last scientific advances in this research field. PMID:24013489

(1) Outer surface of anesthesia machines and patient monitors, and breathing bags are exposed to the contaminated anesthetists' hands and fingers. Disinfection by wiping surface of anesthesia machines with alcohol, and disinfecting hands and fingers with rubbing-type, alcohol-based antiseptics are encouraged. (2) Anesthesia equipments' breathing circuit part is contaminated by patients' breath and respiratory secretions. It is necessary to set rules for exchange of breathing circuit tubes and breathing bags, periodical cleansing and disinfection of canisters as well as inhalation and exhalation valves, and usage of bacteria filters. (3) Anesthesia apparatus (laryngoscope, tracheal tube and suction tube) contact with patients' oral cavity and airway, and thus they are categorized as semi-critical items that require high-level disinfection. PMID:20486566

This article describes a public education program combining the screening process and a follow-up program for teaching victims of emphysema and other respiratory diseases how to better their living condition through proper breathing, avoidance of air pollutants and cigarette smoking, and taking better care of themselves physically. (PD)

Instrument measures metabolic breathing rate and dynamics of human beings in atmospheres ranging from normal air to 100 percent oxygen at ambient pressures from 14.7 to 3.0 psia. Measurements are made at rest or performing tasks up to maximum physical capacity under either zero or normal gravity.

Efficacy of long-term intermittent positive pressure breathing (IPPB) treatment when used as an adjunct to the overall care of ambulatory outpatients with chronic obstructive pulmonary disease. The evaluation compared the use of IPPB with use of a powered nebulizer.

The shift from nasal to oronasal breathing (ONBS) has been observed on 73 subjects with two independent methods. A first group of 63 subjects exercising on a bicycle ergometer at increasing work load (98--196 W) has been observed. On 35 subjects the highest value of ventilation attained with nasal breathing was 40.2 +/- 9.41 . min-1 S.D. Ten subjects breathed through the mouth at all loads, while 5 never opened the mouth. On 13 subjects it was not possible to make reliable measurements. On a second group of 10 subjects utilizing a different techniques which did not need a face mask, the ventilation at which one changes the pattern of breathing was found to be 44.2 +/- 13.51 . min-1 S.D. On the same subjects nasal resistance did not show any correlation with ONBS. It is concluded that ONBS is not solely determined by nasal resistance, though an indirect effect due to hypoventilation and hence to changes in alveolar air composition cannot be ruled out. It is likely that ONBS is also influenced by psychological factors. PMID:569826

The ability of men to exercise while breathing through graded inspiratory resistances was studied in order to define acceptable respiratory mouthpiece assembly standards. Experimental results with subjects wearing breathing masks and walking for 30 min on treadmills were used to calculate expiratory work rates. It is concluded that the airflow must be appropriate to the upper limit of minute ventilation likely to be encountered in the men wearing the apparatus.

The Idaho National Laboratory (INL) deactivated several aging nuclear fuel storage basins. Planners for this effort were greatly concerned that radioactive contamination present on the basin walls could become airborne as the sides of the basins became exposed during deactivation and allowed to dry after water removal. One way to control this airborne contamination was to fix the contamination in place while the pool walls were still submerged. There are many underwater coatings available on the market for marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives were easily applied and adhered well to the substrates (pool wall materials) found in INL fuel pools. Lab-scale experiments were conducted by applying fourteen different commercial underwater coatings to four substrate materials representative of the storage basin construction materials, and evaluating their performance. The coupons included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The evaluation criteria included ease of application, adherence to the four surfaces of interest, no change on water clarity or chemistry, non-hazardous in final applied form and be proven in underwater applications. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected from the underwater coatings tested for application to all four pools. Divers scrubbed loose contamination off the basin walls and floors using a ship hull scrubber and vacuumed up the sludge. The divers then applied the coating using a special powered roller with two separate heated hoses that allowed the epoxy to mix at the roller surface was used to eliminate pot time concerns. The walls were successfully coated and water was removed from the pools with no detectable airborne contamination releases.

A detector apparatus for differentiating between gamma and neutron radiation is provided. The detector includes a pair of differentially shielded Geiger-Mueller tubes. The first tube is wrapped in silver foil and the second tube is wrapped in lead foil. Both the silver and lead foils allow the passage of gamma rays at a constant rate in a gamma ray only field. When neutrons are present, however, the silver activates and emits beta radiation that is also detected by the silver wrapped Geiger-Mueller tube while the radiation detected by the lead wrapped Geiger-Mueller tube remains constant. The amount of radiation impinging on the separate Geiger-Mueller tubes is then correlated in order to distinguish between the neutron and gamma radiations.

Experimental measurements of cosmic ray muon intensity deep underwater aimed at determining a muon absorption curve are of considerable interest, as they allow to reproduce independently the muon energy spectrum at sea level. The comparison of the muon absorption curve in sea water with that in rock makes it possible to determine muon energy losses caused by nuclear interactions. The data available on muon absorption in water and that in rock are not equivalent. Underground measurements are numerous and have been carried out down to the depth of approx. 15km w.e., whereas underwater muon intensity have been measured twice and only down to approx. 3km deep.

Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

A furnace apparatus is designed for treating a nuclear reactor waste solution. The solution is sprayed onto a bed of burning petroleum coke which expels water, the more volatile fission products, and nitrogen oxides. Next, chlorine gas is introduced from below which causes aluminum to volatilize as aluminum chloride and along with it certain fission products including Nb/sup 95/ and Zr/sup 95/. These lose their radioactivity within four years and the long- lived radioactivity remains with the ash, which is stored. (AEC) V) nitrate. (P.C.H.)

An improved mining apparatus for excavating material, such as coal, for example, from an earth formation, such as a coal seam, for example, wherein a miner, having a forward and a rearward cutter, is guided through the coal seam and excavates a borehole therein, the borehole being filled with a working fluid during the operation of the miner, the working fluid facilitating the operation of the miner and providing a vehicle for removing the mined material. Substantially all of the operations of the miner are controlled from the earth's surface thereby eliminating the necessity and accompanying hazards and costs involved in utilizing personnel underground during the mining operations.

1. Apparatus for detonation of high explosive in uniform timing comprising in combination, an outer case, spark gap electrodes insulatedly supported in spaced relationship within said case to form a spark gap, high explosive of the class consisting of pentaerythritol tetranitrate and trimethylene trinitramine substantially free from material sensitive to detonation by impact compressed in surrounding relation to said electrodes including said spark gap under a pressure from about 100 psi to about 500 psi, said spark gap with said compressed explosive therein requiring at least 1000 volts for sparking, and means for impressing at least 1000 volts on said spark gap.

A fastening apparatus is adapted to be inserted and removed from one side of a work piece having an opposite side which is substantially inaccessible to a worker. A first, externally threaded member is threadingly engaged with a receiving structure, and a second member is inserted within corresponding seats or grooves for interlocking the two members. In the preferred embodiment diverting seats are provided for forming the second member into locking engagement between the receiving structure and the first member. In one embodiment, seat structures are provided for engaging frangible panels or the like for high temperature applications.

An apparatus for precisely positioning materials test specimens within the optimum neutron flux path emerging from a neutron source located in a housing. The test specimens are retained in a holder mounted on the free end of a support pivotably mounted and suspended from a movable base plate. The support is gravity biased to urge the holder in a direction longitudinally of the flux path against the housing. Means are provided for moving the base plate in two directions to effect movement of the holder in two mutually perpendicular directions normal to the axis of the flux path.

An apparatus for precisely positioning materials test specimens within the optimum neutron flux path emerging from a neutron source located in a housing. The test specimens are retained in a holder mounted on the free end of a support pivotably mounted and suspended from a movable base plate. The support is gravity biased to urge the holder in a direction longitudinally of the flux path against the housing. Means are provided for moving the base plate in two directions to effect movement of the holder in two mutually perpendicular directions normal to the axis of the flux path.

Quality evaluation of underwater images is a key goal of underwater video image retrieval and intelligent processing. To date, no metric has been proposed for underwater color image quality evaluation (UCIQE). The special absorption and scattering characteristics of the water medium do not allow direct application of natural color image quality metrics especially to different underwater environments. In this paper, subjective testing for underwater image quality has been organized. The statistical distribution of the underwater image pixels in the CIELab color space related to subjective evaluation indicates the sharpness and colorful factors correlate well with subjective image quality perception. Based on these, a new UCIQE metric, which is a linear combination of chroma, saturation, and contrast, is proposed to quantify the non-uniform color cast, blurring, and low-contrast that characterize underwater engineering and monitoring images. Experiments are conducted to illustrate the performance of the proposed UCIQE metric and its capability to measure the underwater image enhancement results. They show that the proposed metric has comparable performance to the leading natural color image quality metrics and the underwater grayscale image quality metrics available in the literature, and can predict with higher accuracy the relative amount of degradation with similar image content in underwater environments. Importantly, UCIQE is a simple and fast solution for real-time underwater video processing. The effectiveness of the presented measure is also demonstrated by subjective evaluation. The results show better correlation between the UCIQE and the subjective mean opinion score. PMID:26513783

Children in a tribe of sea-gypsies from South-East Asia have been found to have superior underwater vision compared to European children. In this study, we show that the improved underwater vision of these Moken children is not due to better contrast sensitivity in general. We also show that European children can achieve the same underwater acuity as the Moken children. After 1 month of underwater training (11 sessions) followed by 4 months with no underwater activities, European children showed improved underwater vision and distinct bursts of pupil constriction. When tested 8 months after the last training session in an outdoor pool in bright sunlight-comparable to light environments in South-East Asia-the children had attained the same underwater acuity as the sea-gypsy children. The achieved performance can be explained by the combined effect of pupil constriction and strong accommodation. PMID:16806388

... this section of the RSIA to the Administrator of FRA. 74 FR 26981, 26982, June 5, 2009, 49 CFR 1.49(oo.... See 73 FR 75207, December 10, 2008, re Docket No. HHS-OS-2009-0025 at http://www.regulations.gov . The... respirators are supplied. See also 74 FR 23815, May 21, 2009, which reopened the comment period until...

An apparatus is described for the measurement of metabolic rate and breathing dynamics in which inhaled and exhaled breath are sensed by sealed, piston-displacement type spirometers. These spirometers electrically measure the volume of inhaled and exhaled breath. A mass spectrometer analyzes simultaneously for oxygen, carbon dioxide, nitrogen and water vapor. Computation circuits are responsive to the outputs of the spirometers, mass spectrometer, temperature, pressure and timing signals and compute oxygen consumption, carbon dioxide production, minute volume and respiratory exchange ratio. A selective indicator provides for read-out of these data at predetermined cyclic intervals.

This study used both an instantaneous net drag force profile and a symmetry timing to evaluate the effect of the breathing action on stroke coordination. Twenty elite swimmers completed a total of six randomised front-crawl towing trials: (i) three breathing trials and (ii) three non-breathing trials. The net drag force was measured using an assisted towing device mounted upon a Kistler force platform, and this equipment towed the swimmer at a constant speed. The net drag force profile was used to create a stroke symmetry index for each swimming trial. Analysis using the symmetry indices identified that the majority of participants demonstrated an asymmetrical instantaneous net drag force stroke profile in both the breathing and non-breathing conditions, despite no significant differences in the time from finger-tip entry to finger-tip exit. Within the breathing condition, the faster swimmers compared to the slower swimmers demonstrated a lesser percentage of overlap between stroke phases on their breathing stroke side. During the non-breathing condition, the faster participants compared to the slower swimmers recorded a reduction in the percentage of overlap between stroke phases and less duration in the underwater stroke on their breathing stroke side. This study identified that the majority of participants demonstrated an asymmetrical net drag force profile within both conditions; however, asymmetry was less prevalent when examining with only the timing symmetry index. PMID:24861056

Mapleson breathing systems are used for delivering oxygen and anaesthetic agents and to eliminate carbon dioxide during anaesthesia. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection. There are five basic types of Mapleson system: A, B, C, D and E depending upon the different arrangements of these components. Mapleson F was added later. For adults, Mapleson A is the circuit of choice for spontaneous respiration where as Mapleson D and its Bains modifications are best available circuits for controlled ventilation. For neonates and paediatric patients Mapleson E and F (Jackson Rees modification) are the best circuits. In this review article, we will discuss the structure of the circuits and functional analysis of various types of Mapleson systems and their advantages and disadvantages. PMID:24249884

Applications of human factors to undersea engineering and the relationship to aerospace science are explored. Cooperative ventures include the TEKTITE underwater habitat and development of better procedures to prevent decompression sickness. Other research involved the use of alternate gases in diving systems, remote-operation vehicles, and diving system tests. PMID:11541030

Underwater robots (or ROVs: Remotely Operated Vehicles as they are typically called in industry) have recently become a very popular instructional STEM activity. Nationally, ROVs have been used in science and technology classrooms for several years in cities such as Seattle, San Diego, Virginia Beach, and other coastal areas. In the past two…

New operational technology for elimination intrauterine hypoxia and asphyxia of the fetus using endoscopic artificial ventilation lungs by respiratory gas was developed. For intrauterine ventilation of fetal lung it is proposed to enter into the uterus a special breathing mask and wear it on the head of the fetus using the original endoscopic technology. The breathing mask, developed by us is connected with external breathingapparatus with a hose. The device is called "intrauterine aqualung". Intrauterine aqualung includes a ventilator and breathing circuit with a special fold-out breathing mask that is put on inside the uterus on the head of fetus like a mesh hat. Controlled by ultrasound the technology of the introduction of the mask inside of the uterus through the natural opening in the cervix and technology of putting on the respiratory mask on the head of the fetus with its head previa were developed. The technology intrauterine ventilation of the fetus lungs by respiratory gas was developed.

A process and apparatus for separating components of a source gas is provided in which more soluble components of the source gas are dissolved in an aqueous solvent at high pressure. The system can utilize hydrostatic pressure to increase solubility of the components of the source gas. The apparatus includes gas recycle throughout multiple mass transfer stages to improve mass transfer of the targeted components from the liquid to gas phase. Separated components can be recovered for use in a value added application or can be processed for long-term storage, for instance in an underwater reservoir.

Hydrogenation reaction apparatus comprising a housing having walls which define a reaction zone and conduits for introducing streams of hydrogen and oxygen into the reaction zone, the oxygen being introduced into a central portion of the hydrogen stream to maintain a boundary layer of hydrogen along the walls of the reaction zone. A portion of the hydrogen and all of the oxygen react to produce a heated gas stream having a temperature within the range of from 1100.degree. to 1900.degree. C., while the boundary layer of hydrogen maintains the wall temperature at a substantially lower temperature. The heated gas stream is introduced into a hydrogenation reaction zone and provides the source of heat and hydrogen for a hydrogenation reaction. There also is provided means for quenching the products of the hydrogenation reaction. The present invention is particularly suitable for the hydrogenation of low-value solid carbonaceous materials to provide high yields of more valuable liquid and gaseous products.

An improved collecting apparatus for small aquatic or airborne organisms such as plankton, larval fish, insects, etc. The improvement constitutes an apertured removal container within which is retained a collecting bag, and which is secured at the apex of a conical collecting net. Such collectors are towed behind a vessel or vehicle with the open end of the conical net facing forward for trapping the aquatic or airborne organisms within the collecting bag, while allowing the water or air to pass through the apertures in the container. The container is readily removable from the collecting net whereby the collecting bag can be quickly removed and replaced for further sample collection. The collecting bag is provided with means for preventing the bag from being pulled into the container by the water or air flowing therethrough.

In France, diving activities are practised by a large number of people, included recreational or sport divers, commercial and military divers. Different diving technics are used, depending on depth and duration of underwater interventions: human intervention under pressure (diving), one atmosphere submarine, remotely operated vehicle (ROV). The diver used specific equipment and procedures with air, heliox (oxygen -helium), hydrox (oxygen-hydrogen) or hydreliox (oxygen-hydrogen-helium) breathing gas mixtures; and for decompression, specific tables adapted to gas mixtures and underwater time exposures. In 1988, six Comex and French Navy divers worked at a record depth of 534 msw with hydreliox and in 1992 a world record onshore dive at 701 msw was performed by Comex in Marseille. These dives showed the efficiency of hydrogen diving at very deep depth. Among a lot of submarines built for undersea works, the latest in the range of Comex's innovative submarines, the "Remora 2000" combines the functions and instrumentation of an oceanographic subsea vessel with eye catching design of a recreational submarine. Now, ROV's replace more and more the diver on oil subsea offshore fields. PMID:8963715

This report describes the epimeletic (or "caregiving") behavior produced by members of a group of Atlantic bottlenose dolphins (Tursiops truncatus) and the possible role of the ailing animal's distress call in eliciting such behavior. Epimeletic behavior in cetaceans most typically involves forms of support provided to a distressed, injured, or dying animal (Caldwell & Caldwell, 1966). Analyses of underwater video and corresponding acoustic recordings revealed a distressed dolphin (the DD) that frequently produced what are most likely distress calls, often paired with the emission of long bubble streams. The frequency of her whistle production was positively correlated with the frequency of the supporting behaviors the DD received from other dolphins. These helping behaviors included raft formations, lifts, and stimulating pushes that were predominantly directed toward the upper third of the DD's body, all of which appeared to be directed towards bringing the DD toward the surface so that she could breathe. This is the first documented underwater account of multiple wild bottlenose dolphins providing epimeletic care to a distressed conspecific, and highlights the possible role of distress calls in such scenarios. PMID:25898942

The confinement of surface plasmon modes in flat nanoparticles gives rise to plasmonic breathing modes. With a vanishing net dipole moment, breathing modes do not radiate, i.e., they are optically dark. Having thus escaped optical detection, breathing modes were only recently revealed in silver nanodisks with electron energy loss spectroscopy in an electron microscope. We show that for disk diameters >200 nm, retardation induced by oblique optical illumination relaxes the optically dark character. This makes breathing modes and thus the full plasmonic mode spectrum accessible to optical spectroscopy. The experimental spectroscopy data are in excellent agreement with numerical simulations.

Compressive sensing (CS) theory has drawn great interest and led to new imaging techniques in many different fields. In recent years, the FAU/HBOI OVOL has conducted extensive research to study the CS based active electro-optical imaging system in the scattering medium such as the underwater environment. The unique features of such system in comparison with the traditional underwater electro-optical imaging system are discussed. Building upon the knowledge from the previous work on a frame based CS underwater laser imager concept, more advantageous for hover-capable platforms such as the Hovering Autonomous Underwater Vehicle (HAUV), a compressive line sensing underwater imaging (CLSUI) system that is more compatible with the conventional underwater platforms where images are formed in whiskbroom fashion, is proposed in this paper. Simulation results are discussed.

Practical limitations of underwater imaging systems are reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and the resolution necessary for target discovery and identification. The advent of high power lasers operating in the oceanic transmission window of the visible spectrum (blue-green portion) has led to improved experimental illumination systems for underwater imaging The properties of laser bearm in range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence effect of common volume back scatter to reduce or eliminate noise, increase signal to noise levels. Synchronously scanned systems rely on the highly collimated nature of the laser beam for spatial rejection of common volume back scatter. A synchronous, raster-scanning underwater laser imaging system (UWLIS) has been developed at Lawrence liver-more National Laboratory. The present UWLIS system differs from earlier synchronous scanners in its ability to scan in two dimensions at conventional video frame rate (30 Hz). The imaging performance of the present UWLIS was measured at distances of up to 6.3 AL (at a physical distance of 15.2 meters) during an in-water tank test and 4.5 to 5.0 AL (at a physical distance of 30 meters) during open water oceanic testing. The test results indicate that the UWLIS system is already capable of extending the underwater imaging range beyond that of conventional floodlight illuminated SIT cameras. The real or near real time frame rates of the UWLIS make possible operations in a mode in which the platform speed is randomly varied. This is typical of the operational environment in which the platform is often maneuvered above and around rugged seafloor terrain`s and obstacles.

Hydrogenation reaction apparatus is described comprising a housing having walls which define a reaction zone and conduits for introducing streams of hydrogen and oxygen into the reaction zone, the oxygen being introduced into a central portion of the hydrogen stream to maintain a boundary layer of hydrogen along the walls of the reaction zone. A portion of the hydrogen and all of the oxygen react to produce a heated gas stream having a temperature within the range of from 1,100 to 1,900 C, while the boundary layer of hydrogen maintains the wall temperature at a substantially lower temperature. The heated gas stream is introduced into a hydrogenation reaction zone and provides the source of heat and hydrogen for a hydrogenation reaction. There also is provided means for quenching the products of the hydrogenation reaction. The present invention is particularly suitable for the hydrogenation of low-value solid carbonaceous materials to provide high yields of more valuable liquid and gaseous products. 2 figs.

There are disclosed two embodiments of wellhead apparatus for use in suspending concentric strings of casing of an offshore well at the ocean floor. For this purpose, an inner hanger to which the inner casing is connected is adapted to be landed within an outer hanger to which the outer casing is connected, each at the ocean floor or ''mudline''. Seating surfaces are formed on the bore of the tubular body of the outer hanger body, and landing surfaces are formed on a circumferentially split landing ring arranged about the tubular body of the inner hanger and having landing surfaces formed thereabout for expansion and contraction within a recess about the tubular hanger body between a contracted position as it is moved vertically within the outer casing and bore of the tubular body of the outer hanger, and an expanded position in which the landing surfaces thereon are landed upon the seating surfaces when disposed opposite thereto. The landing ring is retained in a position for expansion and contraction within the recess by detent means which is releasable, when the landing ring is in landed position, and the weight of the inner casing is slacked off so as to lower the inner hanger body into supported position on the landing ring.

There is disclosed apparatus for use in suspending concentric strings of casing of an offshore well at the ocean floor, wherein at least one hanger for suspending an intermediate casing string is provided with a plurality of vertically spaced, upwardly facing seating surfaces which extend radially inwardly from its bore, and the outer side of such hanger body has a recess thereabout in which a radially expandable ring having a plurality of vertically spaced, downwardly facing landing surfaces is received. As the intermediate hanger body is lowered into the bore of an outer hanger having vertically spaced, upwardly facing seating surfaces extending radially outwardly from its bore, the ring expands radially outwardly to move its landing surfaces into supported positions on the seating surfaces of the outer hanger. As an inner hanger is lowered into the bore of the intermediate hanger, landing surfaces on a radially expandible ring carried within a recess about the outer side of its body are caused to expand with the ring into supported positions on the seating surfaces of the intermediate hanger body. The seating surfaces within the bore of the intermediate hanger body and the recess about its outer side in which the expandible ring is received are on generally the same vertical line.

Laser apparatus is described wherein an active laser element, such as the disc of a face-pumped laser, is mounted in a housing such that the weight of the element is supported by glass spheres which fill a chamber defined in the housing between the walls of the housing and the edges of the laser element. The uniform support provided by the spheres enable the chamber and the pump side of the laser element to be sealed without affecting the alignment or other optical properties of the laser element. Cooling fluid may be circulated through the sealed region by way of the interstices between the spheres. The spheres, and if desired also the cooling fluid may contain material which absorbs radiation at the wavelength of parasitic emissions from the laser element. These parasitic emissions enter the spheres through the interface along the edge surface of the laser element and it is desirable that the index of refraction of the spheres and cooling fluid be near the index of refraction of the laser element. Thus support, cooling, and parasitic suppression functions are all accomplished through the use of the arrangement.

It is well known that the shape of a weld pool can influence the microstructure and segregation pattern of the final solidified weld metal. Mechanical properties and susceptibility to defects are consequently affected by the solidification mode of the weld. In this work the solidification behavior of weld beads deposited in air and underwater wet welding using rutile electrodes were compared. The welds were deposited by gravity feed, on low carbon, manganese steel plates using similar welding conditions. Macroscopic observation of the weld craters showed that welds deposited in air presented an elliptical weld pool. The underwater wet welds, on the other hand, solidified with a tear drop shape. Although the welds differed in shape, their lengths were approximately the same. Microscopic examinations carried out on transverse, normal and longitudinal sections revealed a coarser columnar grain structure in the underwater welds. These results suggest that the tear-drop shaped pool induced solidification in a preferred orientation with segregation more likely in welds deposited under wet conditions. This change in weld pool geometry can be explained by the surface heat loss conditions that occur in a wet weld: slower when covered by the steam bubble and faster in the region in contact with water behind the pool.

Focuses on mapping activities designed to provide simulated experiences that help students understand the techniques used to measure and represent underwater terrain without making direct visual observations. (DDR)

Taiwan is an important trading and maritime channels for many countries since ancient time. Numerous relics lie underwater due to weather, wars, and other factors. In the year of 2006, Bureau of Cultural Heritage (BOCH) entrusted the Underwater Archaeological Team of Academia Sinica to execute the underwater archaeological investigation projects. Currently, we verified 78 underwater targets, with 78 site of those had been recognized as shipwrecks sites. Up to date, there is a collection of 638 underwater objects from different underwater archaeological sites. Those artefacts are distributed to different institutions and museums. As very diverse management methods/systems are applied for every individual institution, underwater cultural heritage data such as survey, excavation report, research, etc. are poorly organized and disseminated for use. For better communication regarding to Taiwan's underwater cultural heritage in every level, a universal format of documentation should be established. By comparing the existing checklist used in Taiwan with guidelines that are followed in other countries, a more intact and appropriate underwater cultural heritage condition documentation system can be established and adapted in Taiwan.

Crocodilians are amphibious reptiles which hunt prey both on land and in water. Previous refractive and anatomical studies have suggested that their eyes can focus objects in air and that their ability to refocus the eye underwater may be limited. Examination of the plane of focus of six species of crocodilians both in air and underwater has revealed that they are generally well focused in air for distant targets and severely defocused underwater. These results suggest that sensory systems other than vision must play an important role in prey capture underwater. PMID:3184006

The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included 1) Test Area North (TAN-607) with epoxy painted concrete walls; 2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; 3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and 4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55oF to 80oF dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: · Be easy to apply · Adhere well to the four surfaces of interest · Not change or have a negative impact on water chemistry or clarity · Not be hazardous in final applied form · Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the test results. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected to

Breath testing has the potential to benefit the medical field as a cost-effective, non-invasive diagnostic tool for diseases of the lung and beyond. With growing evidence of clinical worth, standardization of methods, and new sensor and detection technologies the stage is set for breath testing to gain considerable attention and wider application in upcoming years. PMID:21173863

BREATHE is an acronym for Breathe, Reflect, Empathize, Accept, Thank, Hearten, Engage. The addition of Understand allows for a holistic approach to living a healthy and balanced life both inside and outside the classroom. This paper took form as a result of my personal, spiritual journey, as well as my teaching practice. I noticed that the…

Patient assist system for totally disabled persons was developed which permits a person, so paralyzed as to be unable to move, to activate by breathing, a call system to summon assistance, turn the page of a book, ajust his bed, or do any one of a number of other things. System consists of patient assist control and breath actuated switch.

Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

Respiration is primarily regulated for metabolic and homeostatic purposes in the brainstem. However, breathing can also change in response to changes in emotions, such as sadness, happiness, anxiety or fear. Final respiratory output is influenced by a complex interaction between the brainstem and higher centres, including the limbic system and cortical structures. Respiration is important in maintaining physiological homeostasis and co-exists with emotions. In this review, we focus on the relationship between respiration and emotions by discussing previous animal and human studies, including studies of olfactory function in relation to respiration and the piriform-amygdala in relation to respiration. In particular, we discuss oscillations of piriform-amygdala complex activity and respiratory rhythm. PMID:18487316

Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

The circle breathing CO2 absorption system for use during acetylene anesthesia was described by Carl Gauss in 1924/1925. The apparatus was manufactured by Drägerwerk of Lübeck. A considerable number of publications on the apparatus employing the closed circle method of CO2 absorption appeared in the medical press soon thereafter. Later apparatus models, also built by Drägerwerk, were adapted for nitrous oxide-oxygen-ether anesthesia and introduced into practice by Paul Sudeck and Helmut Schmidt. Information about all this was transmitted to America through the German medical press, including the Draeger-Hefte. American anesthesia machine manufacturers began to develop closed circle CO2 absorbers several years later. Claims that the circle breathing CO2 absorption method was introduced into anesthesia practice by Brian Sword are not valid. PMID:10969391

The present review examines studies which have reported on the performance of submerged operators on manual dexterity tasks in the practical arena of the open ocean underwater environment. The previous emphasis on the primacy of the factor situational anxiety, in degrading efficiency, is questioned. The case for environmentally-based factors and performer skill level as potent influences on performance is advanced. In postulating a potential linear relationship between depth of operation and performance decrement for air-breathing divers, the review seeks to stimulate further experimental examination of this important applied issue. PMID:15676579

The paper presents achievements of the Underwater Team at the Faculty of Maritime Technology of the Szczecin Technical University in the field of designing the equipment destined for the underwater monitoring. The multipurpose remotely operated vehicle system is described. Technical specification, some laboratory tank test results, research techniques, operational range, experience and development trends have been discussed.

With funding from the National Science Foundation (NSF), ITEEA members will contribute to the development of a hybrid professional development program designed to facilitate the scale-up of an innovative underwater robotics curriculum. WaterBotics[TM] is an underwater robotics curriculum that targets students in middle and high school classrooms…

Naval activities such as ordnance disposal, demolition and requisite training, can involve detonation of small explosive charges in shallow water that have the potential to harm nearby marine life. Measurements of the underwater sound generated by sub-surface explosions were collected as part of a naval training exercise. In this thesis the noise levels from these explosions will be investigated using peak pressure, sound exposure level and energy spectral density. Measurements of very-low frequency Scholte interface waves will also be presented and used to investigate elastic parameters in the sediment.

The U.S. Geological Survey has used 23 different shotpoints during two seasons of field work in our seismic study of crustal structure in western United States. Without exception, it has been found that under-water shotpoints result in a more efficient conversion of explosive energy into seismic energy than do drilled-hole shotpoints. This experience, together with elimination of drilling costs, has led to the use of underwater shotpoints wherever possible. Three of the 23 shotpoints were in the Pacific Ocean, and for these we have no detailed information on the fish kill. Another six shotpoints were located in inland bodies of water. These are: * Soda Lake near Fallon, Nevada * Mono Lake near Lee Vining, California * Lake Mead near Boulder City, Nevada * Shasta Lake near Redding, California * C.J. Strike Reservoir near Bruneau, Idaho * Lucky Peak Reservoir near Boise, Idaho The 22 high-explosive charges, weighing a total of 95,100 pounds, that were fired in lakes containing fish life resulted in the known death of 2,413 game fish with a total weight of 759 pounds. The average mortality was 110 game fish or 34.5 pounds of game fish killed per average shot of 4,325 pounds of high-explosives.

Underwater imaging is challenging because of the significant attenuation of light due to absorption and scattering of light in water. Using polarization properties of light is one of the options for improving image quality. We present results of imaging of a polarized target in open ocean (Curacao) and coastal (NY Bight) waters. The target in the shape of a square is divided into several smaller squares, each of which is covered with a polarizing film with different polarization orientations or transmission coefficients was placed on a mirror and imaged under water by a green-band full-Stokes polarimetric video camera at the full range of azimuth angles against the Sun. The values of the Stokes vector components from the images are compared with the modeled image of the target using radiative transfer code for the atmosphere-ocean system combined with the simple imaging model. It is shown that even in clear water the impact of the water body on the polarized underwater image is very significant and retrieval of target polarization characteristics from the image is extremely challenging.

The objective of this study is to develop an RGB-D (video + depth) camera that provides three-dimensional image data for use in the haptic feedback of a robotic underwater ordnance recovery system. Two camera systems were developed and studied. The first depth camera relies on structured light (as used by the Microsoft Kinect), where the displacement of an object is determined by variations of the geometry of a projected pattern. The other camera system is based on a Time of Flight (ToF) depth camera. The results of the structural light camera system shows that the camera system requires a stronger light source with a similar operating wavelength and bandwidth to achieve a desirable working distance in water. This approach might not be robust enough for our proposed underwater RGB-D camera system, as it will require a complete re-design of the light source component. The ToF camera system instead, allows an arbitrary placement of light source and camera. The intensity output of the broadband LED light source in the ToF camera system can be increased by putting them into an array configuration and the LEDs can be modulated comfortably with any waveform and frequencies required by the ToF camera. In this paper, both camera were evaluated and experiments were conducted to demonstrate the versatility of the ToF camera.

The needs of undersea defense, and indeed those of the scientific community, overlap those of the offshore oil and gas industry, not least when it comes to subsea operations. They share problems encountered in the design and use of unmanned underwater vehicles, particularly in relation to reliability, efficiency, cost-effectiveness, and capabilities. The U.K. Marine Technology Directorate Ltd. (MTD) is managing a research program - Technology for Unmanned Underwater Vehicles (TUUV) - formulated with the particular aim of solving the problems identified by industry in relation to the operation of UUVs. The overall goal of the first three TUUV phases is to provide a convincing demonstration that the production of such advanced systems is practical, credible and cost-effective. Despite the advances in TUUV1, discussions with operators and program participants show that broad concerns over vehicle operations remain. TUUV2 and TUUV3 will transform the current purely technical and largely independent projects into an integrated concept demonstration that will justify the mainly industrial investment needed to make TUUV4 a reality in time for the millennium.

A method and apparatus for determining the position of and estimating the size of leaks in an evacuating apparatus comprising the use of a testing gas such as helium or hydrogen flowing around said apparatus whereby the testing gas will be drawn in at the site of any leaks.

Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

The inspection of offshore parks, dam walls and other infrastructure under water is expensive and time consuming, because such constructions must be inspected manually by divers. Underwater buildings have to be examined visually to find small cracks, spallings or other deficiencies. Automation of underwater inspection depends on established water-proved imaging systems. Most underwater imaging systems are based on acoustic sensors (sonar). The disadvantage of such an acoustic system is the loss of the complete visual impression. All information embedded in texture and surface reflectance gets lost. Therefore acoustic sensors are mostly insufficient for these kind of visual inspection tasks. Imaging systems based on optical sensors feature an enormous potential for underwater applications. The bandwidth from visual imaging systems reach from inspection of underwater buildings via marine biological applications through to exploration of the seafloor. The reason for the lack of established optical systems for underwater inspection tasks lies in technical difficulties of underwater image acquisition and processing. Lightening, highly degraded images make a computational postprocessing absolutely essential.

Despite the incredible success of insects in colonizing almost every habitat, they remain virtually absent in one major environment--the open sea. A variety of hypotheses have been raised to explain why just a few insect species are present in the ocean, but none of them appears to be fully explanatory. Lice belonging to the family Echinophthiriidae are ectoparasites on different species of pinnipeds and river otters, i.e. they have amphibious hosts, who regularly perform long excursions into the open sea reaching depths of hundreds of meters (thousands of feets). Consequently, lice must be able to support not only changes in their surrounding media, but also extreme variations in hydrostatic pressure as well as breathing in a low oxygen atmosphere. In order to shed some light on the way lice can survive during the diving excursions of their hosts, we have performed a series of experiments to test the survival capability of different instars of Antarctophthirus microchir (Phthiraptera: Anoplura) from South American sea lions Otaria flavescens, when submerged into seawater. These experiments were aimed at analyzing: (a) immersion tolerance along the louse life; (b) lice's ability to obtain oxygen from seawater; (c) physiological responses and mechanisms involved in survival underwater. Our experiments showed that the forms present in non-diving pups--i.e. eggs and first-instar nymphs--were unable to tolerate immersion in water, while following instars and adults, all usually found in diving hosts, supported it very well. Furthermore, as long as the level of oxygen dissolved in water was higher, the lice survival capability underwater increased, and the recovery period after returning to air declined. These results are discussed in relation to host ecology, host exploitation and lice functional morphology. PMID:25449903

Deploying a multi-hop underwater acoustic sensor network (UASN) in a large area brings about new challenges in reliable data transmissions and survivability of network due to the limited underwater communication range/bandwidth and the limited energy of underwater sensor nodes. In order to address those challenges and achieve the objectives of maximization of data delivery ratio and minimization of energy consumption of underwater sensor nodes, this paper proposes a new underwater routing scheme, namely AURP (AUV-aided underwater routing protocol), which uses not only heterogeneous acoustic communication channels but also controlled mobility of multiple autonomous underwater vehicles (AUVs). In AURP, the total data transmissions are minimized by using AUVs as relay nodes, which collect sensed data from gateway nodes and then forward to the sink. Moreover, controlled mobility of AUVs makes it possible to apply a short-range high data rate underwater channel for transmissions of a large amount of data. To the best to our knowledge, this work is the first attempt to employ multiple AUVs as relay nodes in a multi-hop UASN to improve the network performance in terms of data delivery ratio and energy consumption. Simulations, which are incorporated with a realistic underwater acoustic communication channel model, are carried out to evaluate the performance of the proposed scheme, and the results indicate that a high delivery ratio and low energy consumption can be achieved. PMID:22438740

Deploying a multi-hop underwater acoustic sensor network (UASN) in a large area brings about new challenges in reliable data transmissions and survivability of network due to the limited underwater communication range/bandwidth and the limited energy of underwater sensor nodes. In order to address those challenges and achieve the objectives of maximization of data delivery ratio and minimization of energy consumption of underwater sensor nodes, this paper proposes a new underwater routing scheme, namely AURP (AUV-aided underwater routing protocol), which uses not only heterogeneous acoustic communication channels but also controlled mobility of multiple autonomous underwater vehicles (AUVs). In AURP, the total data transmissions are minimized by using AUVs as relay nodes, which collect sensed data from gateway nodes and then forward to the sink. Moreover, controlled mobility of AUVs makes it possible to apply a short-range high data rate underwater channel for transmissions of a large amount of data. To the best to our knowledge, this work is the first attempt to employ multiple AUVs as relay nodes in a multi-hop UASN to improve the network performance in terms of data delivery ratio and energy consumption. Simulations, which are incorporated with a realistic underwater acoustic communication channel model, are carried out to evaluate the performance of the proposed scheme, and the results indicate that a high delivery ratio and low energy consumption can be achieved. PMID:22438740

This book was organized by the Center's East European program and supported primarily by a grant from the Rockefeller Brothers' Fund. This book reports on the new political forces that swept Communist regimes from power throughout the region in 1989 and are now struggling to set up post-Communist governments and institutions. Nor need they do so. This volume does not attempt to be a current account of the state of environmental policy and official institutions in Eastern Europe. New institutions are only slowly taking shape. In the meantime, much of the old apparatus remains in place. The new leaders and parties have found it difficult to cover the economic cost or accept the political risk of imposing expensive environmental controls on the large industrial enterprises that are the principal polluters. In Poland and Hungary we see the real threat of a political backlash from workers facing unemployment when such enterprises lose even part of their state budget subsidy, let alone face new charges for pollution control or penalties for its absence. The separate environmental movement that played a prominent part in the overthrow of Communist power has not, moreover, survived as a powerful separate political party anywhere in Eastern Europe. Its chances appeared greatest in East Germany and Czechoslovakia but in neither place has the Green political organization expanded or even maintained its pre-1989 leverage.

Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

Recent advances in laser and electro optics technology have greatly enhanced the feasibility of active optical probing techniques aimed at the remote sensing of water parameters. This paper describes a LIDAR (laser radar) that has been designed and constructed for underwater probing. The influence of the optical properties of water on the general design parameters of a LIDAR system is considered. Discussion of the specific details in the choice of the constructed LIDAR is given. This system utilizes a cavity dumped argon ion laser transmitter capable of 50 watt peak powers, 10 nanosecond pulses and megahertz pulse repetition rates at 10 different wavelengths in the blue green region of the spectrum. The performance of the system, in proving various types of water, is demonstrated by summarizing the results of initial laboratory and field experiments.

In this work, we deal with the problem of change detection in an underwater scenario given an unblurred-blurred image pair of a planar scene taken at different times. The blur is primarily due to the dynamic nature of the water surface and its nature is space-invariant in the presence of cyclic water flows. Exploiting the sparsity of the induced blur as well as the occlusions, we propose a distort-difference pipeline that employs an alternating minimization framework to perform change detection in the presence of geometric distortions (skew) as well as photometric degradations (blur and global illumination variations). The method can effectively yield both sharp and blurred occluder maps. Using synthetic as well as real data, we demonstrate how the proposed technique advances the state of the art. PMID:26974899

An unmanned underwater vehicle (UUV) was designed inspired by the form and functionality of a Jellyfish. These natural organisms were chosen as bio-inspiration for a multitude of reasons including: efficiency of locomotion, lack of natural predators, proper form and shape to incorporate payload, and varying range of sizes. The structure consists of a hub body surrounded by bell segments and microcontroller based drive system. The locomotion of UUV was achieved by shape memory alloy "Biometal Fiber" actuation which possesses large strain and blocking force with adequate response time. The main criterion in design of UUV was the use of low-profile shape memory alloy actuators which act as artificial muscles. In this manuscript, we discuss the design of two Jellyfish prototypes and present experimental results illustrating the performance and power consumption.

Two fundamental facts control the choice of computational methods in underwater acoustics. One is that over most of the ocean the sound speed varies much more rapidly with depth than in the horizontal directions. The other is that upon going down from the surface, the sound speed usually decreases to a minimum and then increases from there to the bottom. These properties of the medium imply that the ocean often acts as a waveguide, with energy trapped in a depth-band about the sound-speed minimum. One consequence of these facts is that approximation by normal modes is valid over large regions of the ocean, particularly if correction is made for the slow variation of the modes caused by variation in bottom depth and horizontal variation in sound speed. In portions of the ocean where approximation by normal modes is not valid, we may still often use a paraxial approximation. Paraxial approximations may be used when the wave motion is primarily in a single direction, with slow variation of the signal in directions tangent to the wave front. They are often called ``parabolic`` equations in ocean acoustics, but the term ``paraxial`` is standard in other branches of physics, inducting optics and seismology. Finite-difference approximations are also sometimes used in underwater acoustics, but they are much more computationally intensive than normal modes or paraxial approximations. Finite differences are therefore ordinarily used only where these other methods are not valid, such as in shallow water with rapidly varying depth. One could also use finite elements in these instances, but for acoustics problems finite elements are a special class of finite-difference methods. We discuss finite differences only briefly in this report, because they are not generally used in long-range acoustics.

Two fundamental facts control the choice of computational methods in underwater acoustics. One is that over most of the ocean the sound speed varies much more rapidly with depth than in the horizontal directions. The other is that upon going down from the surface, the sound speed usually decreases to a minimum and then increases from there to the bottom. These properties of the medium imply that the ocean often acts as a waveguide, with energy trapped in a depth-band about the sound-speed minimum. One consequence of these facts is that approximation by normal modes is valid over large regions of the ocean, particularly if correction is made for the slow variation of the modes caused by variation in bottom depth and horizontal variation in sound speed. In portions of the ocean where approximation by normal modes is not valid, we may still often use a paraxial approximation. Paraxial approximations may be used when the wave motion is primarily in a single direction, with slow variation of the signal in directions tangent to the wave front. They are often called parabolic'' equations in ocean acoustics, but the term paraxial'' is standard in other branches of physics, inducting optics and seismology. Finite-difference approximations are also sometimes used in underwater acoustics, but they are much more computationally intensive than normal modes or paraxial approximations. Finite differences are therefore ordinarily used only where these other methods are not valid, such as in shallow water with rapidly varying depth. One could also use finite elements in these instances, but for acoustics problems finite elements are a special class of finite-difference methods. We discuss finite differences only briefly in this report, because they are not generally used in long-range acoustics.

Piezoelectric materials have been used in underwater acoustic transducers for nearly a century. In this paper, we reviewed four different types of piezoelectric materials: piezoelectric ceramics, single crystals, composites, and polymers, which are widely used in underwater acoustic transducers nowadays. Piezoelectric ceramics are the most dominant material type and are used as a single-phase material or one of the end members in composites. Piezoelectric single crystals offer outstanding electromechanical response but are limited by their manufacturing cost. Piezoelectric polymers provide excellent acoustic impedance matching and transducer fabrication flexibility although their piezoelectric properties are not as good as ceramics and single crystals. Composites combined the merits of ceramics and polymers and are receiving increased attention. The typical structure and electromechanical properties of each type of materials are introduced and discussed with respect to underwater acoustic transducer applications. Their advantages and disadvantages are summarized. Some of the critical design considerations when developing underwater acoustic transducers with these materials are also touched upon.

This paper develops and compares different sensor network architecture designs that can be used for monitoring underwater pipeline infrastructures. These architectures are underwater wired sensor networks, underwater acoustic wireless sensor networks, RF (Radio Frequency) wireless sensor networks, integrated wired/acoustic wireless sensor networks, and integrated wired/RF wireless sensor networks. The paper also discusses the reliability challenges and enhancement approaches for these network architectures. The reliability evaluation, characteristics, advantages, and disadvantages among these architectures are discussed and compared. Three reliability factors are used for the discussion and comparison: the network connectivity, the continuity of power supply for the network, and the physical network security. In addition, the paper also develops and evaluates a hierarchical sensor network framework for underwater pipeline monitoring. PMID:22346669

Global navigation satellite systems (GNSS) are widely used for the localization and the navigation of unmanned and remotely operated vehicles (ROV). In contrast to ground or aerial vehicles, GNSS cannot be employed for autonomous underwater vehicles (AUV) without the use of a communication link to the water surface, since satellite signals cannot be received underwater. However, underwater autonomous navigation is still possible using self-localization methods which determines the relative location of an AUV with respect to a reference location using inertial measurement units (IMU), depth sensors and even sometimes radar or sonar imaging. As an alternative or a complementary solution to common underwater reckoning techniques, we present the first results of a feasibility study of an active-imaging-based localization method which uses a range-gated active-imaging system and can yield radiometric and odometric information even in turbid water.

A sleever apparatus includes an inner member with a central passage through which an item to be sleeved is passed. An outer member surrounds the inner member and defines a space between the members for holding a supply of containment material, which is preferably plastic sleeving. The apparatus has a handle which allows a user to hold the apparatus and walk the apparatus along the length of the item to be sleeved. As the user passes the item through the sleever apparatus, the containment material exits through a slit at one end of the apparatus in order to contain the item. The sleever apparatus may be formed of disposable materials, such as cardboard, and may be intended for a single use application. Alternatively, the sleever apparatus may be comprised of more permanent materials such as PVC or fiberglass. The sleever apparatus may include a serrated end for cutting the containment material and may include appropriate tubing and valves for either directing an inert gas into the containment material around the item or for withdrawing air from within the containment material in order to create a vacuum. In one embodiment, the sleever apparatus has a cartridge that can be replaced with another cartridge once the supply of the containment material has been depleted.

In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

The growing need for underwater observation and sub-sea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, bio-geochemical, evolutionary and ecological changes in the sea, ocean and lake environments and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. We present models of three kinds of optical wireless communication links a) a line-of-sight link, b) a modulating retro-reflector link and c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered lighted it was possible to mitigate this decrease in some cases. We conclude from the analysis that a high data rate underwater optical wireless network is a feasible solution for emerging applications such as UUV to UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

Investigates the effectiveness of breathing instruction on the breath management, performance, and knowledge of breathing among college-level brass musicians. Finds that breathing instruction significantly improved the breath management and knowledge of the breathing for the experimental groups and the musical range of the trombone players in the…

Peripartum cardiomyopathy (PPCM) is one of the potentially life-threatening complications of pregnancy. We report a case of a 36-year-old female patient who presented with shortness of breath, swelling of feet after giving birth to triplets, and her tests revealed that left ventricle is dilated with its diameter on the borderline and she had EF 35% with advanced systolic dysfunction. Anterior wall and septum were severely hypokinetic. In the presence of these findings, the patient was evaluated as PPCM. PPCM must be considered in the differential diagnosis of a patient presenting with shortness of breath and swelling of feet, which are also common in pregnancy. PMID:26649031

Peripartum cardiomyopathy (PPCM) is one of the potentially life-threatening complications of pregnancy. We report a case of a 36-year-old female patient who presented with shortness of breath, swelling of feet after giving birth to triplets, and her tests revealed that left ventricle is dilated with its diameter on the borderline and she had EF 35% with advanced systolic dysfunction. Anterior wall and septum were severely hypokinetic. In the presence of these findings, the patient was evaluated as PPCM. PPCM must be considered in the differential diagnosis of a patient presenting with shortness of breath and swelling of feet, which are also common in pregnancy. PMID:26649031

This paper examines nearshore underwater-acoustic channel modeling concepts and compares channel-state information requirements against existing modeling capabilities. This process defines a subset of candidate acoustic models suitable for simulating signal propagation in underwater communications. Underwater-acoustic communications find many practical applications in coastal oceanography, and networking is the enabling technology for these applications. Such networks can be formed by establishing two-way acoustic links between autonomous underwater vehicles and moored oceanographic sensors. These networks can be connected to a surface unit for further data transfer to ships, satellites, or shore stations via a radio-frequency link. This configuration establishes an interactive environment in which researchers can extract real-time data from multiple, but distant, underwater instruments. After evaluating the obtained data, control messages can be sent back to individual instruments to adapt the networks to changing situations. Underwater networks can also be used to increase the operating ranges of autonomous underwater vehicles by hopping the control and data messages through networks that cover large areas. A model of the ocean medium between acoustic sources and receivers is called a channel model. In an oceanic channel, characteristics of the acoustic signals change as they travel from transmitters to receivers. These characteristics depend upon the acoustic frequency, the distances between sources and receivers, the paths followed by the signals, and the prevailing ocean environment in the vicinity of the paths. Properties of the received signals can be derived from those of the transmitted signals using these channel models. This study concludes that ray-theory models are best suited to the simulation of acoustic signal propagation in oceanic channels and identifies 33 such models that are eligible candidates.

Underwater blasts propagate further and injure more readily than equivalent air blasts. Development of effective personal protection and countermeasures, however, requires knowledge of the currently unknown human tolerance to underwater blast. Current guidelines for prevention of underwater blast injury are not based on any organized injury risk assessment, human data or experimental data. The goal of this study was to derive injury risk assessments for underwater blast using well-characterized human underwater blast exposures in the open literature. The human injury dataset was compiled using 34 case reports on underwater blast exposure to 475 personnel, dating as early as 1916. Using severity ratings, computational reconstructions of the blasts, and survival information from a final set of 262 human exposures, injury risk models were developed for both injury severity and risk of fatality as functions of blast impulse and blast peak overpressure. Based on these human data, we found that the 50% risk of fatality from underwater blast occurred at 302±16 kPa-ms impulse. Conservatively, there is a 20% risk of pulmonary injury at a kilometer from a 20 kg charge. From a clinical point of view, this new injury risk model emphasizes the large distances possible for potential pulmonary and gut injuries in water compared with air. This risk value is the first impulse-based fatality risk calculated from human data. The large-scale inconsistency between the blast exposures in the case reports and the guidelines available in the literature prior to this study further underscored the need for this new guideline derived from the unique dataset of actual injuries in this study. PMID:26606655

Underwater blasts propagate further and injure more readily than equivalent air blasts. Development of effective personal protection and countermeasures, however, requires knowledge of the currently unknown human tolerance to underwater blast. Current guidelines for prevention of underwater blast injury are not based on any organized injury risk assessment, human data or experimental data. The goal of this study was to derive injury risk assessments for underwater blast using well-characterized human underwater blast exposures in the open literature. The human injury dataset was compiled using 34 case reports on underwater blast exposure to 475 personnel, dating as early as 1916. Using severity ratings, computational reconstructions of the blasts, and survival information from a final set of 262 human exposures, injury risk models were developed for both injury severity and risk of fatality as functions of blast impulse and blast peak overpressure. Based on these human data, we found that the 50% risk of fatality from underwater blast occurred at 302±16 kPa-ms impulse. Conservatively, there is a 20% risk of pulmonary injury at a kilometer from a 20 kg charge. From a clinical point of view, this new injury risk model emphasizes the large distances possible for potential pulmonary and gut injuries in water compared with air. This risk value is the first impulse-based fatality risk calculated from human data. The large-scale inconsistency between the blast exposures in the case reports and the guidelines available in the literature prior to this study further underscored the need for this new guideline derived from the unique dataset of actual injuries in this study. PMID:26606655

A heating apparatus includes at least one combustion air inlet, a reverse-draft hearth having a grill positioned within a hearth plate, an ash receptacle for recovering combustion wastes, a fume outlet combustion chamber positoned under the reverse-draft hearth, and a heat recovery device. A heat transport and exchange fluid is adapted to be fed through the heat recovery device, and it circulates through the device in order to recover heat generated in the hearth. The heat recovery device also includes at least one casing positioned beneath the hearth, over the ash receptacle, and which is spaced from the walls of the heating apparatus. The rear portion of the casing is connected to the hearth plate so as to block combustion gases so that the combustion gases will pass over and thereafter under the casing prior to leaving the apparatus via the fume outlet.

The diver's nervous system is extremely sensitive to high ambient pressure, which is the sum of atmospheric and hydrostatic pressure. Neurological complications associated with diving are a difficult diagnostic and therapeutic challenge. They occur in both commercial and recreational diving and are connected with increasing interest in the sport of diving. Hence it is very important to know the possible complications associated with this kind of sport. Complications of the nervous system may result from decompression sickness, pulmonary barotrauma associated with cerebral arterial air embolism (AGE), otic and sinus barotrauma, high pressure neurological syndrome (HPNS) and undesirable effect of gases used for breathing. The purpose of this review is to discuss the range of neurological symptoms that can occur during diving accidents and also the role of patent foramen ovale (PFO) and internal carotid artery (ICA) dissection in pathogenesis of stroke in divers. PMID:25666773

The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

As one of the components of the Project ACTIVE (All Children Totally Involved Exercising) Teacher Training Model Kit, the manual is designed to enable the educator to organize, conduct, and evaluate individualized-personalized physical education programs for children (prekindergarten through high school) with breathing problems. An introductory…

Describes: (1) a variable inductor suitable for an inductance-capacitance bridge consisting of a fixed cylindrical solenoid and a moveable solenoid; (2) long-range apparatus for demonstrating falling bodies; and (3) an apparatus using two lasers to demonstrate ray optics. (SK)

An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

An apparatus which thermally protects sensitive components in tools used in a geothermal borehole. The apparatus comprises a Dewar within a housing. The Dewar contains heat pipes such as brass heat pipes for thermally conducting heat from heat sensitive components to a heat sink such as ice.

The disclosure is directed to an apparatus for thermally protecting sensitive components in tools used in a geothermal borehole. The apparatus comprises a Dewar within a housing. The Dewar contains heat pipes such as brass heat pipes for thermally conducting heat from heat sensitive components such as electronics to a heat sink such as ice.

An apparatus for treating garbage is described. The apparatus has a conveyor, a continuous incinerator receiving garbage from the conveyor, a device for cooling ash carried out of the continuous incinerator, a device for filtering the ash, a pipe for inducing exhaust from the continuous incinerator to a water tank for removing particles and water-soluble components from the exhaust. 1 fig.

A functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome indicated that breath holding served an operant function, primarily to gain access to attention. Use of extinction, scheduled attention, and a picture card communication system decreased breath holding. (Author/SW)

Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can

This paper presents the development of an underwater omnidirectional multi-camera system (OMS) based on a commercially available six-camera system, originally designed for land applications. A full calibration method is presented for the estimation of both the intrinsic and extrinsic parameters, which is able to cope with wide-angle lenses and non-overlapping cameras simultaneously. This method is valid for any OMS in both land or water applications. For underwater use, a customized housing is required, which often leads to strong image distortion due to refraction among the different media. This phenomena makes the basic pinhole camera model invalid for underwater cameras, especially when using wide-angle lenses, and requires the explicit modeling of the individual optical rays. To address this problem, a ray tracing approach has been adopted to create a field-of-view (FOV) simulator for underwater cameras. The simulator allows for the testing of different housing geometries and optics for the cameras to ensure a complete hemisphere coverage in underwater operation. This paper describes the design and testing of a compact custom housing for a commercial off-the-shelf OMS camera (Ladybug 3) and presents the first results of its use. A proposed three-stage calibration process allows for the estimation of all of the relevant camera parameters. Experimental results are presented, which illustrate the performance of the calibration method and validate the approach. PMID:25774707

Due to the absorptive and scattering nature of water, the characteristic of underwater image is different with it in the air. Underwater image is characterized by their poor visibility and noise. Getting clear original image and image processing are two important problems to be solved in underwater clear vision area. In this paper a new approach technology is presented to solve these problems. Firstly, an inhomogeneous illumination method is developed to get the clear original image. Normal illumination image system and inhomogeneous illumination image system are used to capture the image in same distance. The result shows that the contrast and definition of processed image is get great improvement by inhomogeneous illumination method. Secondly, based on the theory of photon transmitted in the water and the particularity of underwater target detecting, the characters of laser scattering on underwater target surface and spatial and temporal characters of oceanic optical channel have been studied. Based on the Monte Carlo simulation, we studied how the parameters of water quality and other systemic parameters affect the light transmitting through water at spatial and temporal region and provided the theoretical sustentation of enhancing the SNR and operational distance.

Underwater photogrammetry using consumer grade photographic equipment can be feasible for different applications, e.g. archaeology, biology, industrial inspections, etc. The use of a camera underwater can be very different from its terrestrial use due to the optical phenomena involved. The presence of the water and camera pressure housing in front of the camera act as additional optical elements. Spherical dome ports are difficult to manufacture and consequently expensive but at the same time they are the most useful for underwater photogrammetry as they keep the main geometric characteristics of the lens unchanged. Nevertheless, the manufacturing and alignment of dome port pressure housing components can be the source of unexpected changes of radial and decentring distortion, source of systematic errors that can influence the final 3D measurements. The paper provides a brief introduction of underwater optical phenomena involved in underwater photography, then presents the main differences between flat and dome ports to finally discuss the effect of manufacturing on 3D measurements in two case studies.

The first cases of underwater blast injury appeared in the scientific literature in 1917, and thousands of service members and civilians were injured or killed by underwater blast during WWII. The prevalence of underwater blast injuries and occupational blasting needs led to the development of many safety standards to prevent injury or death. Most of these standards were not supported by experimental data or testing. In this review, we describe existing standards, discuss their origins, and we comprehensively compare their prescriptions across standards. Surprisingly, we found that most safety standards had little or no scientific basis, and prescriptions across standards often varied by at least an order of magnitude. Many published standards traced back to a US Navy 500 psi guideline, which was intended to provide a peak pressure at which injuries were likely to occur. This standard itself seems to have been based upon a completely unfounded assertion that has propagated throughout the literature in subsequent years. Based on the limitations of the standards discussed, we outline future directions for underwater blast injury research, such as the compilation of epidemiological data to examine actual injury risk by human beings subjected to underwater blasts. PMID:26415071

Hughes Aircraft has performed exploratory wind tunnel studies of compressed carriage missile designs having extendable Ring Wing and wrap-around tail control surfaces. These force and moment data indicate that significant improvements in a missile's lift and aerodynamic efficiency can be realized. Low speed test results of these data were used to estimate potential underwater improved hydrodynamic characteristics that a Ring Wing and wrap-around tails can bring to an advanced torpedo design. Estimates of improved underwater flight performance of a heavyweight torpedo (4000 lbs.) having an extendable Ring Wing and wrap-around tails were made. The compressed volume design of this underwater missile is consistent with tube-launch constraints and techniques. Study results of this novel Ring Wing torpedo design include extended flight performance in range and endurance due to lowered speeds capable of sustaining underwater level flight. Correspondingly, reduced radiated noise for enhanced stealth qualities is projected. At high speeds, greater maneuverability and aimpoint selection can be realized by a Ring Wing underwater missile.

This paper presents the development of an underwater omnidirectional multi-camera system (OMS) based on a commercially available six-camera system, originally designed for land applications. A full calibration method is presented for the estimation of both the intrinsic and extrinsic parameters, which is able to cope with wide-angle lenses and non-overlapping cameras simultaneously. This method is valid for any OMS in both land or water applications. For underwater use, a customized housing is required, which often leads to strong image distortion due to refraction among the different media. This phenomena makes the basic pinhole camera model invalid for underwater cameras, especially when using wide-angle lenses, and requires the explicit modeling of the individual optical rays. To address this problem, a ray tracing approach has been adopted to create a field-of-view (FOV) simulator for underwater cameras. The simulator allows for the testing of different housing geometries and optics for the cameras to ensure a complete hemisphere coverage in underwater operation. This paper describes the design and testing of a compact custom housing for a commercial off-the-shelf OMS camera (Ladybug 3) and presents the first results of its use. A proposed three-stage calibration process allows for the estimation of all of the relevant camera parameters. Experimental results are presented, which illustrate the performance of the calibration method and validate the approach. PMID:25774707

Emerging biosensor approaches may prove useful in reducing false positives and improving detection probabilities for unexploded ordnance (UXO) and underwater explosives. NRL researchers previously developed a biosensor that was field-tested and validated for use in environmental remediation to detect explosives in groundwater. The sensor relies on the selective recognition by antibodies of target analytes, including the common explosives TNT and RDX. Laboratory work has demonstrated that sensors based on these displacement immunoassay formats can detect explosives at the part-per-trillion level in seawater. More recently, participating in an Office of Naval Research program on Chemical Sensing in the Marine Environment (CSME), tests were conducted in controlled underwater experiments at San Clemente, CA and Duck, NC. Simulated UXO targets, autonomous underwater vehicles (AUV) and multiple sensor approaches were used to demonstrate the feasibility of underwater chemical sensing. Efforts are now underway to integrate the biosensor into an underwater platform as part of a broader sensor system. We will describe results of these studies and outline possible operational scenarios for applications in harbor security.

Simulated breath drive mechanism was developed as subsystem to breathing metabolic simulator. Mechanism reproduces complete range of human breath rate, breath depth, and breath waveform, as well as independently controlled functional residual capacity. Mechanism was found capable of simulating various individual human breathing characteristics without any changes of parts.

In order to have a high level of accuracy of measurement in underwater close-range photogrammetry, this article deals with a study of three varieties of model equations according to the way of imaging upon the water. First, the paper makes a careful analysis for the two varieties of theoretical equations and finds out that there are some serious limitations in practical application and has an in-depth study for the third model equation. Second, one special project for this measurement has designed correspondingly. Finally, one rigid antenna has been tested by underwater photogrammetry. The experimental results show that the precision of 3D coordinates measurement is 0.94mm, which validates the availability and operability in practical application with this third equation. It can satisfy the measurement requirements of refraction correction, improving levels of accuracy of underwater close-range photogrammetry, as well as strong antijamming and stabilization.

We have designed and constructed a magnetic gradiometer for underwater mine detection, location and tracking. The United States Naval Surface Warfare Center (NSWC PC) in Panama City, FL has conducted sea tests of the system using an unmanned underwater vehicle (UUV). The Real-Time Tracking Gradiometer (RTG) measures the magnetic field gradients caused by the presence of a mine in the Earth's magnetic field. These magnetic gradients can then be used to detect and locate a target with the UUV in motion. Such a platform can also be used for other applications, including the detection and tracking of vessels and divers for homeland (e.g., port) security and the detection of underwater pipelines. Data acquired by the RTG in sea tests is presented in this paper.

A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system.

This paper describes experience with respect to underwater work carried out by Remotely Operated Vehicles (ROV's) on the North West Shelf Development Project, North Rankin A field located off the North West coast of Australia. Typical work includes detailed pipeline and platform inspections, underwater support for the installation of gravity anchors and associated guy wires, general construction support, underwater cutting, marine fouling removal, scour protection installation and pipeline stabilization. The paper describes special tooling procedures and systems developed to perform the work. Also presented are new information and statistics associated with bulk marine fouling removal by purpose designed/built remotely operated equipment. Specific data related to time/costs associated with performance of significant aspects of the work are presented.

Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.

This Letter demonstrates a simple method to achieve underwater anisotropic oil-wetting using silicon surfaces with a microgroove array produced by femtosecond laser ablation. The oil contact angles along the direction perpendicular to the grooves are consistently larger than those parallel to the microgroove arrays in water because the oil droplet is restricted by the energy barrier that exists between the non-irradiated domain and the trapped water in the laser-ablated microgrooves. This underwater anisotropic oil-wetting is able to be controlled, and the anisotropy can be tuned from 0° to ∼20° by adjusting the period of the microgroove arrays.

Because of the history of sonar and sonar engineering, the concept of "source level" is widely used to characterize anthropogenic sound sources, but is it useful for sources other than sonar transmitters? The concept and applicability of source level are reviewed for sonar, air guns, explosions, ships, and pile drivers. International efforts toward the harmonization of the terminology for underwater sound and measurement procedures for underwater sound sources are summarized, with particular attention to the initiatives of the International Organization for Standardization. PMID:26610941

This paper details the development of an autonomous motion-control and navigation algorithm for an underwater autonomous vehicle, the Ocean Server IVER3, to track long linear features such as underwater pipelines. As part of this work, the Nonlinear and Autonomous Systems Laboratory (NAS Lab) developed an algorithm that utilizes inputs from the vehicles state of the art sensor package, which includes digital imaging, digital 3-D Sidescan Sonar, and Acoustic Doppler Current Profilers. The resulting algorithms should tolerate real-world waterway with episodic strong currents, low visibility, high sediment content, and a variety of small and large vessel traffic.

An improved apparatus for the melting and casting of uranium is described. A vacuum chamber is positioned over the casting mold and connected thereto, and a rod to pierce the oxide skin of the molten uranium is fitted into the bottom of the melting chamber. The entire apparatus is surrounded by a jacket, and operations are conducted under a vacuum. The improvement in this apparatus lies in the fact that the top of the melting chamber is fitted with a plunger which allows squeezing of the oxide skin to force out any molten uranium remaining after the skin has been broken and the molten charge has been cast.

A method of very thoroughly and quikcly cleaning a guaze electrode used in chemical analyses is given, as well as an automobile cleaning apparatus which makes use of the method. The method generates very little waste solution, and this is very important in analyzing radioactive materials, especially in aqueous solutions. The cleaning apparatus can be used in a larger, fully automated controlled potential coulometric apparatus. About 99.98% of a 5 mg plutonium sample was removed in less than 3 minutes, using only about 60 ml of rinse solution and two main rinse steps.

A mirror plasma apparatus which utilizes shielding by arc discharge to form a blanket plasma and lithium walls to reduce neutron damage to the wall of the apparatus. An embodiment involves a rotating liquid lithium blanket for a tandem mirror plasma apparatus wherein the first wall of the central mirror cell is made of liquid lithium which is spun with angular velocity great enough to keep the liquid lithium against the first material wall, a blanket plasma preventing the lithium vapor from contaminating the plasma.

A lifting, rotating and sealing apparatus for nuclear reactors utilizing rotating plugs above the nuclear reactor core. This apparatus permits rotation of the plugs to provide under the plug refueling of a nuclear core. It also provides a means by which positive top core holddown can be utilized. Both of these operations are accomplished by means of the apparatus lifting the top core holddown structure off the nuclear core while stationary, and maintaining this structure in its elevated position during plug rotation. During both of these operations, the interface between the rotating member and its supporting member is sealingly maintained.

A grinding apparatus for grinding the interior portion of a valve stem receiving area of a valve. The apparatus comprises a faceplate, a plurality of cams mounted to an interior face of the faceplate, a locking bolt to lock the faceplate at a predetermined position on the valve, a movable grinder and a guide tube for positioning an optical viewer proximate the area to be grinded. The apparatus can either be rotated about the valve for grinding an area of the inner diameter of a valve stem receiving area or locked at a predetermined position to grind a specific point in the receiving area.

A pipe crawler apparatus particularly useful for 3-inch and 4-inch diameter pipes is provided. The pipe crawler apparatus uses a gripping apparatus in which a free end of a piston rod is modified with a bearing retaining groove. Bearings, placed within the groove, are directed against a camming surface of three respective pivoting support members. The non-pivoting ends of the support members carry a foot-like gripping member that, upon pivoting of the support member, engages the interior wall of the pipe.

Athletes often complain about breathing problems. This is a crucial issue due to potential implications not only on their general health, but also on their competing performance. Asthma and exercise-induced bronchoconstriction are prevalent conditions in elite athletes, which leads doctors to rely most of the times on asthma medication to treat athletes feeling "out of breath". However, there are several other conditions that may mimic asthma and cause dyspnea in athletes. Effective treatment of dyspnea requires appropriate identification and treatment of all disorders. Proper knowledge and accurate diagnosis of such entities is mandatory, since asthma medication is not effective in those conditions. Herein we review the most common differential diagnosis of dyspnea in athletes, and describe the diagnostic strategies in order to increase awareness and to improve doctor's confidence on dealing with these patients. PMID:26934737

Terrestrial species that forage underwater face challenges because their body parts and senses are adapted for land--for example, it is widely held that mammals cannot use olfaction underwater because it is impossible for them to inspire air (sniff) to convey odorants to the olfactory epithelium. Here I describe a mechanism for underwater sniffing used by the semi-aquatic star-nosed mole (Condylura cristata) and water shrew (Sorex palustris). While underwater, both species exhale air bubbles onto objects or scent trails and then re-inspire the bubbles to carry the smell back through the nose. This newly described behaviour provides a mechanism for mammalian olfaction underwater. PMID:17183311

The underwater security system, used in the Qingdao sailboat game of 2008 Olympic Games, combined multiple underwater cameras with sonar detectors, forms an underwater barrier, which can observe the movement of suspicious objects and get the underwater video images continuously and instantly. The lighting system can provide sufficient illumination matched with target to reach the best imaging result. The whole system with the function of centralized control, depth measurement, leakage alarm and image processing, is the original equipment in domestic underwater antiterrorism optical research area.

The breathing mode is a fundamental normal mode present in Coulomb systems, and may have utility in identifying particle charge and the Debye length of certain systems. The question remains whether this mode can be extended to strongly coupled Yukawa balls [1]. These systems are characterized by particles confined within a parabolic potential well and interacting through a shielded Coulomb potential [2,3]. The breathing modes for a variety of systems in 1, 2, and 3 dimensions are computed by solving the eigenvalue problem given by the dynamical (Hesse) matrix. These results are compared to theoretical investigations that assume a strict definition for a breathing mode within the system, and an analysis is made of the most fitting model to utilize in the study of particular systems of complex plasmas [1,4]. References [1] T.E. Sheridan, Phys. of Plasmas. 13, 022106 (2006)[2] C. Henning et al., Phys. Rev. E 74, 056403 (2006)[3] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)[4] C. Henning et al., submitted for publication

While the statistical mechanical description of DNA has a long tradition, renewed interest in DNA melting from a physics perspective is nourished by measurements of the fluctuation dynamics of local denaturation bubbles by single molecule spectroscopy. The dynamical opening of DNA bubbles (DNA breathing) is supposedly crucial for biological functioning during, for instance, transcription initiation and DNA's interaction with selectively single-stranded DNA binding proteins. Motivated by this, we consider the bubble breathing dynamics in a heteropolymer DNA based on a (2+1)-variable master equation and complementary stochastic Gillespie simulations, providing the bubble size and the position of the bubble along the sequence as a function of time. We utilize new experimental data that independently obtain stacking and hydrogen bonding contributions to DNA stability. We calculate the spectrum of relaxation times and the experimentally measurable autocorrelation function of a fluorophore-quencher tagged basepair, and demonstrate good agreement with fluorescence correlation experiments. A significant dependence of opening probability and waiting time between bubble events on the local DNA sequence is revealed and quantified for a promoter sequence of the T7 phage. The strong dependence on sequence, temperature and salt concentration for the breathing dynamics of DNA found here points at a good potential for nanosensing applications by utilizing short fluorophore-quencher dressed DNA constructs. PMID:17237209

Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

It is currently estimated that the economic burden for obstructive sleep apnea syndrome (OSAS) cases not coming to medical attention is steadily increasing, thus making OSAS a major public health concern. For its increasing incidence among the common population, the interest of researchers and clinicians has been recently directed to the study of pathological mechanisms underlying sleep disorders. Current opinion is that airway inflammation and oxidative stress play a crucial role in the pathophysiology of OSAS. Recently there has been increasing interest in the investigation of lungs by non-invasive means measuring the exhaled breath volatile mediators, such as nitric oxide (NO), carbon monoxide (CO), ethane and pentane and finally the non-volatile substances in the liquid phase of exhalate, termed breath condensate. The non-invasiveness of these techniques for the study of airways affected by different respiratory disorders and among those, the OSAS, makes these ideally suited for the evaluation and serial monitoring of patients. Notwithstanding the increasing number of scientific contributions on the use of the exhaled markers in sleep disorders, at the moment, their use is not completely suitable for clinical application. An important contribution to the increase of our knowledge on exhaled markers and for their possible concrete application in clinical practice may come from future studies using proteomics, genomics and metabolomics. In this review, we focus on exhaled breath analysis giving an update on its general aspects, its application in OSAS, and finally its actual clinical applicability and areas for future direction. PMID:22003329

This photograph depicts an air-breathing rocket engine prototype in the test bay at the General Applied Science Lab facility in Ronkonkoma, New York. Air-breathing engines, known as rocket based, combined-cycle engines, get their initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn hydrogen fuel, as opposed to a rocket that must carry its own oxygen, thus reducing weight and flight costs. Once the vehicle has accelerated to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the craft into orbit or sustain it to suborbital flight speed. NASA's Advanced Space Transportation Program at Marshall Space Flight Center, along with several industry partners and collegiate forces, is developing this technology to make space transportation affordable for everyone from business travelers to tourists. The goal is to reduce launch costs from today's price tag of $10,000 per pound to only hundreds of dollars per pound. NASA's series of hypersonic flight demonstrators currently include three air-breathing vehicles: the X-43A, X-43B and X-43C.

Technologies including NMR logging apparatus and methods are disclosed. Example NMR logging apparatus may include surface instrumentation and one or more downhole probes configured to fit within an earth borehole. The surface instrumentation may comprise a power amplifier, which may be coupled to the downhole probes via one or more transmission lines, and a controller configured to cause the power amplifier to generate a NMR activating pulse or sequence of pulses. Impedance matching means may be configured to match an output impedance of the power amplifier through a transmission line to a load impedance of a downhole probe. Methods may include deploying the various elements of disclosed NMR logging apparatus and using the apparatus to perform NMR measurements.

A sealing apparatus in a gas turbine. The sealing apparatus includes a seal housing apparatus coupled to a disc/rotor assembly so as to be rotatable therewith during operation of the gas turbine. The seal housing apparatus comprises a base member, a first leg portion, a second leg portion, and spanning structure. The base member extends generally axially between forward and aft rows of rotatable blades and is positioned adjacent to a row of stationary vanes. The first leg portion extends radially inwardly from the base member and is coupled to the disc/rotor assembly. The second leg portion is axially spaced from the first leg portion, extends radially inwardly from the base member, and is coupled to the disc/rotor assembly. The spanning structure extends between and is rigidly coupled to each of the base member, the first leg portion, and the second leg portion.

Describes an apparatus for viewing one- and two-dimensional collisions and coupled pendulums on an overhead projector. Suggested demonstrations for the two-dimensional colliding balls and for the two-dimensional coupled pendulums are provided. (JN)

Apparatus for use in alpha particle counting with such as photomultiplier tubes, comprising a platform and linkage mechanism whereby samples are moved in linear manner toward and away from ends of the photomultiplier tubes.

An improved apparatus and method for growing crystals from a melt employing a heat pipe, consisting of one or more sections, each section serving to control temperature and thermal gradients in the crystal as it forms inside the pipe.

We present a novel method for real-time 3-D body-shape measurement during breathing based on the laser multiple-line triangulation principle. The laser projector illuminates the measured surface with a pattern of 33 equally inclined light planes. Simultaneously, the camera records the distorted light pattern from a different viewpoint. The acquired images are transferred to a personal computer, where the 3-D surface reconstruction, shape analysis, and display are performed in real time. The measured surface displacements are displayed with a color palette, which enables visual feedback to the patient while breathing is being taught. The measuring range is approximately 400×600×500 mm in width, height, and depth, respectively, and the accuracy of the calibrated apparatus is +/-0.7 mm. The system was evaluated by means of its capability to distinguish between different breathing patterns. The accuracy of the measured volumes of chest-wall deformation during breathing was verified using standard methods of volume measurements. The results show that the presented 3-D measuring system with visual feedback has great potential as a diagnostic and training assistance tool when monitoring and evaluating the breathing pattern, because it offers a simple and effective method of graphical communication with the patient.

Stress corrosion cracking (SCC) is one of the major reasons to reduce the reliability of aged reactor components. Toshiba has been developing underwater laser welding onto surface of the aged components as maintenance and repair techniques. Because most of the reactor internal components to apply this underwater laser welding technique have 3-dimensional shape, effect of welding positions and welded shapes are examined and presented in this report. (authors)

An improved cryopumping apparatus which comprises a cryopumping space which may be alternately opened and closed from the surrounding area by moveable panels, trubular cryopanels within said cryopumping space through which a coolant such as liquid helium may be passed, and an apparatus for spraying liquid argon onto said cylindrical cryopanels in order to enhance the cryogenic entrapment of such low-z ions, atoms, and molecules as hydrogen and helium.

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

An apparatus is describe for charging electric storage batteries, the apparatus comprising: (a) a host computer for providing charging information to and receiving status information from at least one slave computer by means of a data link; and (b) at least one control module coupled to the slave computer for applying charging current to at least one electric storage battery in response to instructions received from the slave computer, and for providing feedback and status information to the slave computer.

A reduced gravity fiber pulling apparatus (FPA) was constructed in order to study the effects of gravity on glass fiber formation. The apparatus was specifically designed and built for use on NASA's KC-135 aircraft. Four flights have been completed to date during which E-glass fiber was successfully produced in simulated zero, high, and lunar gravity environments. In addition simulated lunar soil samples were tested for their fiber producing properties using the FPA.

A portable, hand-held electric arc saw apparatus comprising a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc between the blade and a workpiece of opposite polarity. Electrically conducting means are provided on said frame for transmitting current to said blade. A pair of freely movable endless belts in the form of crawler treads are employed to facilitate movement of the apparatus relative to the workpiece.

A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

An apparatus is described for dissolving a nuclear reactor fuel element in strong acid solutlon. The vapors and entrained liquid resulting from the violent reaction of dissolution are led into a reflux condenser which discharges, not directly back into the top of the reaction vessel in the conventional manner, but by a route leading to the bottom of the apparatus, thereby utilizing the energy of the reaction to bring about a circulation of the solution. (AEC)

GPS-based positioning for AUV is a field of active researches, which integrates DGPS, radio sonobuoy, DSP, high speed data transmission technology with underwater telecommunication technogy. Many problems remain to be solved for GPS application to AUV because of the peculiarity of underwater environment. Some subjects in a GPS-based positioning system for AUV are reviewed in the paper. The development of underwater positioning and underwater GPS technology is introduced first. Secondly, the methods of underwater positioning are analyzed, followed with GPS-based AUV positioning algorithms. Thirdly, the origin of GPS error and its countermeasures are tudied. Finally, a conclusion is drawn that the GPS-based positioning system can provide high precesion positioning for 3D AUV in real time. It is promising in underwater applications. Some key technologies in underwater positioning are presented for future work.

Houston-based Astro Technology Inc. used a partnership with Johnson Space Center to pioneer an advanced fiber-optic monitoring system for offshore oil pipelines. The company's underwater adhesives allow it to retrofit older deepwater systems in order to measure pressure, temperature, strain, and flow properties, giving energy companies crucial data in real time and significantly decreasing the risk of a catastrophe.

A key innovation in the history of whales was the evolution of a sonar system together with high-frequency hearing. Fossils of an archaic toothed whale's inner ear bones provide clues for a stepwise emergence of underwater echolocation ability. PMID:27554653

An underwater vehicle includes a shaft with a propeller disposed thereon; a generator/motor having a stator and a rotor, the rotor being operable to rotate with the propeller; at least one energy storage device connected to the generator/motor; and a controller for setting the generator/motor in a charge mode, a propulsion mode and an idle mode.

Results of an underwater video fuel survey in KE Basin using a high resolution camera system are presented. Quantitative and qualitative information on fuel degradation are given, and estimates of the total fraction of ruptured fuel elements are provided. Representative photographic illustrations showing the range of fuel conditions observed in the survey are included.

In this thesis, we present a study of several problems related to underwater point to point communications and network formation. We explore techniques to improve the achievable data rate on a point to point link using better physical layer techniques and then study sensor cooperation which improves the throughput and reliability in an underwater network. Robust point-to-point communications in underwater networks has become increasingly critical in several military and civilian applications related to underwater communications. We present several physical layer signaling and detection techniques tailored to the underwater channel model to improve the reliability of data detection. First, a simplified underwater channel model in which the time scale distortion on each path is assumed to be the same (single scale channel model in contrast to a more general multi scale model). A novel technique, which exploits the nature of OFDM signaling and the time scale distortion, called Partial FFT Demodulation is derived. It is observed that this new technique has some unique interference suppression properties and performs better than traditional equalizers in several scenarios of interest. Next, we consider the multi scale model for the underwater channel and assume that single scale processing is performed at the receiver. We then derive optimized front end pre-processing techniques to reduce the interference caused during single scale processing of signals transmitted on a multi-scale channel. We then propose an improvised channel estimation technique using dictionary optimization methods for compressive sensing and show that significant performance gains can be obtained using this technique. In the next part of this thesis, we consider the problem of sensor node cooperation among rational nodes whose objective is to improve their individual data rates. We first consider the problem of transmitter cooperation in a multiple access channel and investigate the stability of

Marine mussels and barnacles are sessile biofouling organisms that adhere to a number of surfaces in wet environments and maintain remarkably strong bonds. Previous synthetic approaches to mimic biological wet adhesive properties have focused mainly on the catechol moiety, present in mussel foot proteins (mfps), and especially rich in the interfacial mfps, for example, mfp-3 and -5, found at the interface between the mussel plaque and substrate. Barnacles, however, do not use Dopa for their wet adhesion, but are instead rich in noncatecholic aromatic residues. Due to this anomaly, we were intrigued to study the initial contact adhesion properties of copolymerized acrylate films containing the key functionalities of barnacle cement proteins and interfacial mfps, for example, aromatic (catecholic or noncatecholic), cationic, anionic, and nonpolar residues. The initial wet contact adhesion of the copolymers was measured using a probe tack testing apparatus with a flat-punch contact geometry. The wet contact adhesion of an optimized, bioinspired copolymer film was ∼15.0 N/cm(2) in deionized water and ∼9.0 N/cm(2) in artificial seawater, up to 150 times greater than commercial pressure-sensitive adhesive (PSA) tapes (∼0.1 N/cm(2)). Furthermore, maximum wet contact adhesion was obtained at ∼pH 7, suggesting viability for biomedical applications. PMID:27046671

Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney.

Hydrogen breath tests using various substrates like glucose, lactulose, lactose and fructose are being used more and more to diagnose small intestinal bacterial overgrowth (SIBO) and lactose or fructose malabsorption. Though quantitative culture of jejunal aspirate is considered as gold standard for the diagnosis of SIBO, hydrogen breath tests, in spite of their low sensitivity, are popular for their non-invasiveness. Glucose hydrogen breath test is more acceptable for the diagnosis of SIBO as conventionally accepted double-peak criterion on lactulose hydrogen breath test is very insensitive and recently described early-peak criterion is often false positive. Hydrogen breath test is useful to diagnose various types of sugar malabsorption. Technique and interpretation of different hydrogen breath tests are outlined in this review. PMID:21860825

Key points Sleep disordered breathing (SDB) is common and the severity increases as pregnancy progresses. Frequent snoring, older age and high pre-pregnancy body mass index (>25 kg⋅m−2) could be reliable indicators for SDB in early pregnancy. SDB screening tools, including questionnaires, used in the nonpregnant population have poor predictive ability in pregnancy. Accumulating evidence suggests that SDB during pregnancy may be associated with increased risk of adverse pregnancy outcomes, including gestational diabetes and pre-eclampsia. However, the results should be interpreted cautiously because several studies failed to adjust for potential maternal confounders and have other study limitations. There are no pregnancy-specific practice guidelines for SDB treatment. Many clinicians and practices follow recommendations for the treatment in the general population. Women with pre-existing SDB might need to be reassessed, particularly after the sixth month of pregnancy, because symptoms can worsen with nasal congestion and weight gain. Educational aims To highlight the prevalence and severity of sleep disordered breathing (SDB) in the pregnant population. To inform readers about risk factors for SDB in pregnancy. To explore the impact of SDB on adverse maternal and fetal outcomes, and biological pathways for associated adverse maternal and fetal outcomes. To introduce current management options for SDB in pregnancy, including medical and behavioural approaches. Sleep disordered breathing (SDB) is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the

Breathing signals are one set of physiological data that may provide information regarding the mechanisms that cause SIDS. Isolated breathing pauses have been implicated in fatal events. Other features of interest include slow amplitude modulation of the breathing signal, a phenomenon whose origin is unclear, and periodic breathing. The latter describes a repetitive series of apnea, and may be considered an extreme manifestation of amplitude modulation with successive cessations of breathing. Rhythmicity is defined to assess the impact of amplitude modulation on breathing signals and describes the extent to which frequency components remain constant for the duration of the signal. The wavelet transform was used to identify sections of constant frequency components within signals. Rhythmicity can be evaluated for all the frequency components in a signal, for individual frequencies. The rhythmicity of eight breathing epochs from sleeping infants at high and low risk for SIDS was calculated. Initial results show breathing from infants at high risk for SIDS exhibits greater rhythmicity of modulating frequencies than breathing from low risk infants.

The chemical neuroanatomy of breathing must ultimately encompass all the various neuronal elements physiologically identified in brainstem respiratory circuits and their apparent aggregation into “compartments” within the medulla and pons. These functionally defined respiratory compartments in the brainstem provide the major source of input to cranial motoneurons controlling the airways, and to spinal motoneurons activating inspiratory and expiratory pump muscles. This review provides an overview of the neuroanatomy of the major compartments comprising brainstem respiratory circuits, and a synopsis of the transmitters used by their constituent respiratory neurons. PMID:18706532

... size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and ... volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs ...

... respiratory system conduct air to the lungs, such as the trachea (windpipe) which branches into smaller structures ... the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the ...

Data concerning heart rate (HR), stroke volume (SV), and cardiac output (CO) during dynamic apnoea (DA) were collected from 10 healthy male, elite divers by means of an impedance cardiograph adapted to the underwater environment (C. O. Re., from 2C Technologies Inc, Italy). Three trials were performed by the divers in a 3-m-deep pool with a water temperature of 25°C: 3-minute head-out immersion during normal breathing (A), till exhaustion immersed at the surface (B) and at 3m depth (C). Both B and C conditions did not led to changes in HR, SV and CO compared to A. Data indicate that typical diving response consisting in a reduction of HR, SV and CO was not present during DA, probably due to sympathetic activation induced by exercise during DA, which partially obscured the effects of the diving response. Moreover, this study highlights the innovative role of our portable, impedance cardiography device, i.e. the C. O. Re., in easily assessing cardiodynamic changes in subjects engaged in exercise schedules including phases of underwater, dynamic apnoea.

This special section highlights some of the important work presented at the Breath Analysis Summit 2011, which was held in Parma (Italy) from 11 to 14 September 2011. The meeting, which was jointly organized by the International Association for Breath Research and the University of Parma, was attended by more than 250 delegates from 33 countries, and offered 34 invited lectures and 64 unsolicited scientific contributions. The summit was organized to provide a forum to scientists, engineers and clinicians to present their latest findings and to meet industry executives and entrepreneurs to discuss key trends, future directions and technologies available for breath analysis. A major focus was on nitric oxide, exhaled breath condensate, electronic nose, mass spectrometry and newer sensor technologies. Medical applications ranged from asthma and other respiratory diseases to gastrointestinal disease, occupational diseases, critical care and cancer. Most people identify breath tests with breathalysers used by police to estimate ethanol concentration in blood. However, breath testing has far more sophisticated applications. Breath analysis is rapidly evolving as a new frontier in medical testing for disease states in the lung and beyond. Every individual has a breath fingerprint-or 'breathprint'-that can provide useful information about his or her state of health. This breathprint comprises the many thousands of molecules that are expelled with each breath we exhale. Breath research in the past few years has uncovered the scientific and molecular basis for such clinical observations. Relying on mass spectrometry, we have been able to identify many such unique substances in exhaled breath, including gases, such as nitric oxide (NO) and carbon monoxide (CO), and a wide array of volatile organic compounds. Exhaled breath also carries aerosolized droplets that can be collected as an exhaled breath condensate that contains endogenously produced non-volatile compounds. Breath

Conventional methods for estimating cardiopulmonary variables usually require complex gas analyzers and the active co-operation of the patient. Therefore, they are not compatible with the crowded environment of the intensive care unit (ICU) or operating theatre, where patient co-operation is typically impossible. However, it is these patients that would benefit the most from accurate estimation of cardiopulmonary variables, because of their critical condition. This paper describes the results of a collaborative development between an anesthesiologists and biomedical engineers to create a compact and non-invasive system for the measurement of cardiopulmonary variables such as lung volume, airway dead space volume, and pulmonary blood flow. In contrast with conventional methods, the compact apparatus and non-invasive nature of the proposed method allow it to be used in the ICU, as well as in general clinical settings. We propose the use of a non-invasive method, in which tracer gases are injected into the patient's inspired breath, and the concentration of the tracer gases is subsequently measured. A novel breath-by-breath tidal ventilation model is then used to estimate the value of a patient's cardiopulmonary variables. Experimental results from an artificial lung demonstrate minimal error in the estimation of known parameters using the proposed method. Results from analysis of a cohort of 20 healthy volunteers (within the Oxford University Hospitals NHS Trust) show that the values of estimated cardiopulmonary variables from these subjects lies within the expected ranges. Advantages of this method are that it is non-invasive, compact, portable, and can perform analysis in real time with less than 1 min of acquired respiratory data. PMID:27170849

Apparatus for processing coal to prevent the creation of extreme fines and to extract pyrites from the principal coal fractions in which there are two air circulating circuits having processing components which cooperate in their respective circuits to result initially in substantial extraction of fines in the first circuit while releasing principal granulated coal fractions and pyrites to the second circuit where specific gravity separation of the pyrites and principal coal fractions occur. The apparatus includes a source of drying heat added to the air moving in the circuits and delivered at the places where surface moisture drying is most effective. Furthermore, the apparatus is operated so as to reduce coal to a desired size without creating an excessive volume of extreme fines, to separate pyrites and hard to grind components by specific gravity in a region where fines are not present, and to use the extreme fines as a source of fuel to generate drying heat.

An apparatus for fixing computational latency within a deterministic region on a network comprises a network interface modem, a high priority module and at least one deterministic peripheral device. The network interface modem is in communication with the network. The high priority module is in communication with the network interface modem. The at least one deterministic peripheral device is connected to the high priority module. The high priority module comprises a packet assembler/disassembler, and hardware for performing at least one operation. Also disclosed is an apparatus for executing at least one instruction on a downhole device within a deterministic region, the apparatus comprising a control device, a downhole network, and a downhole device. The control device is near the surface of a downhole tool string. The downhole network is integrated into the tool string. The downhole device is in communication with the downhole network.

A robot arm apparatus is provided for inspecting and/or maintaining an interior of a steam generator which has an outside wall and a port for accessing the interior of the steam generator. The robot arm apparatus includes a flexible movable conduit for conveying inspection and/or maintenance apparatus from outside the steam generator to the interior of the steam generator. The flexible conduit has a terminal working end which is translated into and around the interior of the steam generator. Three motors located outside the steam generator are employed for moving the terminal working end inside the steam generator in ``x,`` ``y,`` and ``z`` directions, respectively. Commonly conducted inspection and maintenance operations include visual inspection for damaged areas, water jet lancing for cleaning sludge deposits, core boring for obtaining sludge deposits, and scrubbing of internal parts.

An apparatus that can return a payload to a known orientation after unknown motion, without requiring external power or complex mechanical systems. The apparatus comprises a faceted cage that causes the system to rest in a stable position and orientation after arbitrary motion. A gimbal is mounted with the faceted cage and holds the payload, allowing the payload to move relative to the stable faceted cage. The payload is thereby placed in a known orientation by the interaction of gravity with the geometry of the faceted cage, the mass of the system, and the motion of the payload and gimbal. No additional energy, control, or mechanical actuation is required. The apparatus is suitable for use in applications requiring positioning of a payload to a known orientation after arbitrary or uncontrolled motion, including remote sensing and mobile robot applications.

An improved apparatus for ultrasonic nebulization of liquid samples or suspensions in which the piezoelectric transducer is protected from chemical attack and erosion. The transducer is protected by being bonded to the inner surface of a glass plate which forms one end wall of a first hollow body provided with apparatus for circulating a fluid for cooling and stabilizing the transducer. The glass plate, which is one-half wavelength in thickness to provide an acoustically coupled outer nebulizing surface, seals an opening in a second hollow body which encloses an aerosol mixing chamber. The second body includes apparatus for delivering the sample solution to the nebulizing surface, a gas inlet for providing a flow of carrier gas for transporting the aerosol of the nebulized sample and an aerosol outlet.

The Navy Clothing and Textile Research Facility (NCTRF) designed and fabricated a thermal energy test apparatus to permit evaluation of the heat protection provided by crash crew firefighter's proximity clothing materials against radiant and convective heat loads, similar to those found outside the flame zone of aircraft fuel fires. The apparatus employs electrically operated quartz lamp radiant heaters and a hot air convective heater assembly to produce the heat load conditions the materials to be subjected to, and is equipped with heat flux sensors of different sensitivities to measure the incident heat flux on the sample material as well as the heat flux transmitted by the sample. Tests of the apparatus have shown that it can produce radiant heat flux levels equivalent to those estimated to be possible in close proximity to large aircraft fuel fires, and can produce convective heat fluxes equivalent to those measured in close proximity to aircraft fuel fires at upwind and sidewind locations. Work was performed in 1974.

An apparatus and method for making multiparameter light scattering measurements from suspensions of biological particles is described. Fourteen of the sixteen Mueller matrix elements describing the particles under investigation can be substantially individually determined as a function of scattering angle and probing radiations wavelength, eight elements simultaneously for each of two apparatus configurations using an apparatus which incluees, in its simplest form, two polarization modulators each operating at a chosen frequency, one polarizer, a source of monochromatic electromagnetic radiation, a detector sensitive to the wavelength of radiation employed, eight phase-sensitive detectors, and appropriate electronics. A database of known biological particle suspensions can be assembled, and unknown samples can be quickly identified once measurements are performed on it according to the teachings of the subject invention, and a comparison is made with the database.

Apparatus for transferring gas from a first container to a second container of higher pressure was devised. A free-piston compressor having a driving piston and cylinder, and a smaller diameter driven piston and cylinder, comprise the apparatus. A rod member connecting the driving and driven pistons functions for mutual reciprocation in the respective cylinders. A conduit may be provided for supplying gas to the driven cylinder from the first container. Also provided is apparatus for introducing gas to the driving piston, to compress gas by the driven piston for transfer to the second higher pressure container. The system is useful in transferring spacecraft cabin oxygen into higher pressure containers for use in extravehicular activities.

A robot arm apparatus is provided for inspecting and/or maintaining an interior of a steam generator which has an outside wall and a port for accessing the interior of the steam generator. The robot arm apparatus includes a flexible movable conduit for conveying inspection and/or maintenance apparatus from outside the steam generator to the interior of the steam generator. The flexible conduit has a terminal working end which is translated into and around the interior of the steam generator. Three motors located outside the steam generator are employed for moving the terminal working end inside the steam generator in "x", "y", and "z" directions, respectively. Commonly conducted inspection and maintenance operations include visual inspection for damaged areas, water jet lancing for cleaning sludge deposits, core boring for obtaining sludge deposits, and scrubbing of internal parts.

A robot arm apparatus is provided for inspecting and/or maintaining an interior of a steam generator which has an outside wall and a port for accessing the interior of the steam generator. The robot arm apparatus includes a flexible movable conduit for conveying inspection and/or maintenance apparatus from outside the steam generator to the interior of the steam generator. The flexible conduit has a terminal working end which is translated into and around the interior of the steam generator. Three motors located outside the steam generator are employed for moving the terminal working end inside the steam generator in "x", "y", and "z" directions, respectively. Commonly conducted inspection and maintenance operations include visual inspection for damaged areas, water jet lancing for cleaning sludge deposits, core boring for obtaining sludge deposits, and scrubbing of internal parts.

A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine. PMID:17153053

A breathing air garment is disclosed for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap. 17 figs.

BACKGROUND: The mechanisms underlying breathing exercises have not been fully elucidated. OBJECTIVES: To evaluate the impact of four on breathing exercises (diaphragmatic breathing, inspiratory sighs, sustained maximal inspiration and intercostal exercise) the on breathing pattern and thoracoabdominal motion in healthy subjects. METHOD: Fifteen subjects of both sexes, aged 23±1.5 years old and with normal pulmonary function tests, participated in the study. The subjects were evaluated using the optoelectronic plethysmography system in a supine position with a trunk inclination of 45° during quiet breathing and the breathing exercises. The order of the breathing exercises was randomized. Statistical analysis was performed by the Friedman test and an ANOVA for repeated measures with one factor (breathing exercises), followed by preplanned contrasts and Bonferroni correction. A p<0.005 value was considered significant. RESULTS: All breathing exercises significantly increased the tidal volume of the chest wall (Vcw) and reduced the respiratory rate (RR) in comparison to quiet breathing. The diaphragmatic breathing exercise was responsible for the lowest Vcw, the lowest contribution of the rib cage, and the highest contribution of the abdomen. The sustained maximal inspiration exercise promoted greater reduction in RR compared to the diaphragmatic and intercostal exercises. Inspiratory sighs and intercostal exercises were responsible for the highest values of minute ventilation. Thoracoabdominal asynchrony variables increased significantly during diaphragmatic breathing. CONCLUSIONS: The results showed that the breathing exercises investigated in this study produced modifications in the breathing pattern (e.g., increase in tidal volume and decrease in RR) as well as in thoracoabdominal motion (e.g., increase in abdominal contribution during diaphragmatic breathing), among others. PMID:25590447

Apparatus attachable to an ultrasonic drilling machine for drilling deep holes in very hard materials, such as boron carbide, is provided. The apparatus utilizes a hollow spindle attached to the output horn of the ultrasonic drilling machine. The spindle has a hollow drill bit attached at the opposite end. A housing surrounds the spindle, forming a cavity for holding slurry. In operation, slurry is provided into the housing, and into the spindle through inlets while the spindle is rotating and ultrasonically reciprocating. Slurry flows through the spindle and through the hollow drill bit to cleanse the cutting edge of the bit during a drilling operation. 3 figs.

Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

An apparatus for determining the content of a fissile material within a solution by detecting delayed fission neutrons emitted by the fissile material after it is temporarily irradiated by a neutron source. The apparatus comprises a container holding the solution and having a portion defining a neutron source cavity centrally disposed within the container. The neutron source cavity temporarily receives the neutron source. The container has portions defining a plurality of neutron detector ports that form an annular pattern and surround the neutron source cavity. A plurality of neutron detectors count delayed fission neutrons emitted by the fissile material. Each neutron detector is located in a separate one of the neutron detector ports.

An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location is described. The apparatus includes a projection system for displaying to a patient a series of visual stimuli, a response switch enabling him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

An expendable oceanographic sensor apparatus is deployed from an airplane or a ship to make oceanographic observations in a profile of the surface-to-ocean floor, while deployed on the floor, and then a second profile when returning to the ocean surface. The device then records surface conditions until on-board batteries fail. All data collected is stored and then transmitted from the surface to either a satellite or other receiving station. The apparatus is provided with an anchor that causes descent to the ocean floor and then permits ascent when the anchor is released. Anchor release is predetermined by the occurrence of a pre-programmed event.

A microelectromechanical (MEM) ratcheting apparatus is disclosed which includes an electrostatic or thermal actuator that drives a moveable member in the form of a ring gear, stage, or rack. Motion is effected by one or more reciprocating pawls driven by the actuator in a direction that is parallel to, in line with, or tangential to the path. The reciprocating pawls engage indexing elements (e.g. teeth or pins) on the moveable member to incrementally move the member along a curved or straight path with the ability to precisely control and determine the position of the moveable member. The MEM apparatus can be formed on a silicon substrate by conventional surface micromachining methods.

Apparatus attachable to an ultrasonic drilling machine for drilling deep holes in very hard materials, such as boron carbide, is provided. The apparatus utilizes a hollow spindle attached to the output horn of the ultrasonic drilling machine. The spindle has a hollow drill bit attached at the opposite end. A housing surrounds the spindle, forming a cavity for holding slurry. In operation, slurry is provided into the housing, and into the spindle through inlets while the spindle is rotating and ultrasonically reciprocating. Slurry flows through the spindle and through the hollow drill bit to cleanse the cutting edge of the bit during a drilling operation.

The invention is a device for splicing submarine coaxial cable underwater on the seafloor with a simple push-on operation to restore and maintain electrical and mechanical strength integrity; the splice device is mateable directly with the severed ends of a coaxial cable to be repaired. Splicing assemblies comprise a dielectric pressure compensating fluid filled guide cavity, a gelled castor oil cap and wiping seals for exclusion of seawater, electrical contacts, a cable strength restoration mechanism, and a pressure compensation system for controlled extrusion of and depletion loss prevention of dielectric seal fluid during cable splicing. A splice is made underwater by directly inserting prepared ends of coaxial cable, having no connector attachments, into splicing assemblies.

We performed computer simulations of the WIGWAM underwater experiment with a 2-D hydro-code, CALE. First, we calculated the bubble pulse and the signal strength at the closest gauge in one-dimensional geometry. The calculation shows excellent agreement with the measured data. Next, we made two-dimensional simulations of WIGWAM applying the gravity over-pressure, and calculated the signals at three selected gauge locations where measurements were recorded. The computed peak pressures at those gauge locations come well within the 15% experimental error bars. The signal at the farthest gauge is of the order of 200 bars. This is significant, because at this pressure the CALE output can be linked to a hydro-acoustics computer program, NPE Code (Nonlinear Progressive Wave-equation Code), to analyze the long distance propagation of acoustical signals from the underwater explosions on a global scale.

Underwater gliders are autonomous underwater vehicles that profile vertically by changing their buoyancy and use wings to move horizontally. Gliders are useful for sustained observation at relatively fine horizontal scales, especially to connect the coastal and open ocean. In this review, research topics are grouped by time and length scales. Large-scale topics addressed include the eastern and western boundary currents and the regional effects of climate variability. The accessibility of horizontal length scales of order 1 km allows investigation of mesoscale and submesoscale features such as fronts and eddies. Because the submesoscales dominate vertical fluxes in the ocean, gliders have found application in studies of biogeochemical processes. At the finest scales, gliders have been used to measure internal waves and turbulent dissipation. The review summarizes gliders' achievements to date and assesses their future in ocean observation.

Retrieving and understanding global flow characteristics from local sensory measurements is a challenging but extremely relevant problem in fields such as defense, robotics, and biomimetics. It is an inverse problem in that the goal is to translate local information into global flow properties. In this talk we present techniques for optimization of sensory layouts within the context of an idealized underwater locomotory system. Using techniques from fluid mechanics and control theory, we show that, under certain conditions, local measurements can inform the submerged body about its orientation relative to the ambient flow, and allow it to recognize local properties of shear flows. We conclude by commenting on the relevance of these findings to underwater navigation in engineered systems and live organisms.

Underwater gliders are autonomous underwater vehicles that profile vertically by changing their buoyancy and use wings to move horizontally. Gliders are useful for sustained observation at relatively fine horizontal scales, especially to connect the coastal and open ocean. In this review, research topics are grouped by time and length scales. Large-scale topics addressed include the eastern and western boundary currents and the regional effects of climate variability. The accessibility of horizontal length scales of order 1 km allows investigation of mesoscale and submesoscale features such as fronts and eddies. Because the submesoscales dominate vertical fluxes in the ocean, gliders have found application in studies of biogeochemical processes. At the finest scales, gliders have been used to measure internal waves and turbulent dissipation. The review summarizes gliders' achievements to date and assesses their future in ocean observation. PMID:26291384

We investigated underwater nuclear effects by computer simulations. First, we computed a long distance wave propagation in water by the 1-D LASNEX code by modeling the energy source and the underwater environment. The pressure-distance data were calculated for two quite different yields; pressures range from 300 GPa to 15 MPa. They were found to be in good agreement with Snay's theoretical points and the Wigwam measurements. The computed data also agree with the similarity solution at high pressures and the empirical equation at low pressures. After completion of the 1-D study, we investigated a free surface effect commonly referred to as irregular surface rarefaction by applying two hydrocodes (LASNEX and ALE), linked at the appropriate time. Using these codes, we simulated near-surface explosions for three depths of burst (3 m, 21 m and 66.5 m), which represent the strong, intermediate, and weak surface shocks, respectively.

Improvised Explosive Devices (IEDs) have presented a major threat in the wars in Afghanistan and Iraq. These devices are powerful homemade land mines that can be small and easily hidden near roadsides. They are then remotely detonated when Coalition Forces pass by either singly or in convoys. Their rapid detection, classification and destruction is key to the safety of troops in the area. These land based bombs will have an analogue in the underwater theater especially in ports, lakes, rivers and streams. These devices may be used against Americans on American soil as an element of the global war on terrorism (GWOT) Rapid detection and classification of underwater improvised explosive devices (UIED) is critical to protecting innocent lives and maintaining the day to day flow of commerce. This paper will discuss a strategy and tool set to deal with this potential threat.

Matched-field processing is a new technique for processing ocean acoustic data measured by an array of hydrophones. It produces estimates of the location of sources of acoustic energy. This method differs from source localization techniques in other disciplines in that it uses the complex underwater acoustic environment to improve the accuracy of the source localization. An unexplored problem in matched-field processing has been to separate multiple sources within a matched-field ambiguity function. Underwater acoustic processing is one of many disciplines where a synthesis of computer graphics and image processing is producing new insight. The benefits of different volume visualization algorithms for matched-field display are discussed. The authors show how this led to a template matching scheme for identifying a source within the matched-field ambiguity function that can help move toward an automated source localization process.

... SCHOOL VESSELS Inspection and Certification Drydocking Or Hauling Out § 169.230 Underwater Survey in Lieu... procedure for carrying out the underwater survey; (2) The time and place of the underwater survey; (3)...

... SCHOOL VESSELS Inspection and Certification Drydocking Or Hauling Out § 169.230 Underwater Survey in Lieu... procedure for carrying out the underwater survey; (2) The time and place of the underwater survey; (3)...

The paper provides an overview of a Hybrid Underwater Camera (HUC) system combining sonar with a range-gated laser camera system. The sonar is the BlueView P900-45, operating at 900kHz with a field of view of 45 degrees and ranging capability of 60m. The range-gated laser camera system is based on the third generation LUCIE (Laser Underwater Camera Image Enhancer) sensor originally developed by the Defence Research and Development Canada. LUCIE uses an eye-safe laser generating 1ns pulses at a wavelength of 532nm and at the rate of 25kHz. An intensified CCD camera operates with a gating mechanism synchronized with the laser pulse. The gate opens to let the camera capture photons from a given range of interest and can be set from a minimum delay of 5ns with increments of 200ps. The output of the sensor is a 30Hz video signal. Automatic ranging is achieved using a sonar altimeter. The BlueView sonar and LUCIE sensors are integrated with an underwater computer that controls the sensors parameters and displays the real-time data for the sonar and the laser camera. As an initial step for data integration, graphics overlays representing the laser camera field-of-view along with the gate position and width are overlaid on the sonar display. The HUC system can be manually handled by a diver and can also be controlled from a surface vessel through an umbilical cord. Recent test data obtained from the HUC system operated in a controlled underwater environment will be presented along with measured performance characteristics.

An underwater sound source is described that may be ejectably mounted on any mobile device that travels over water, to facilitate in the location and recovery of the device when submerged. A length of flexible line maintains a connection between the mobile device and the sound source. During recovery, the sound source is located be particularly useful in the recovery of spent rocket motors that bury in the ocean floor upon impact.

We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

A child with a long standing history of cyanotic breath holding attacks presented with acute respiratory distress. Subsequent investigation established that her clinical condition was caused by tracheomalacia. We hypothesise that tracheomalacia might be an under recognised contributor to cyanotic breath holding attacks, the pathogenesis of which is poorly understood. PMID:10999873

Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that...

A calorimeter apparatus for measuring high temperature thermophysical properties of materials is disclosed which includes a containerless heating apparatus in which the specimen is suspended and heated by electron bombardment.

An aplanatic Fresnel lens was developed in a previous study to reduce the thickness of underwater acoustic lenses. Showing better convergence properties than aplanatic biconvex and hyperbolic Fresnel lenses, the aplanatic Fresnel lens had limitations in terms of frequency and number of waves owing to its shape. An underwater aplanatic Straubel acoustic mirror, the concept o which is based on a Straubel mirror, was designed to remove the two limitations of aplanatic Fresnel lenses. When the lens is used for underwater imaging sonar, the range resolution deteriorates because of these problems. The shape of the aplanatic Straubel mirror was designed using a numerical optimization method, and its convergence properties were evaluated in simulations. The mirror could correct spherical and coma aberrations in accordance with ray theory. In a comparison of the aplanatic Straubel mirror with an aplanatic Fresnel lens, the mirror had less coma aberration and field curvature than the lens. Additionally, the aplanatic Straubel mirror did not have the two limitations of the lens. Therefore, the aplanatic Straubel mirror showed better convergence than the aplanatic Fresnel lens.

The preliminary underwater welding study described forms part of a European funded research program (EUREKA EU194) which involves a feasibility study into laser welding applications in the offshore oil industry. An investigation was undertaken using a 1.2 KW carbon dioxide laser for underwater butt welding of BS 4360 43A and 50D steel, in order to assess the quality of the welds and to achieve an understanding of the laser/water/material interaction. Using a high-speed camera, the temporal behavior of the melt pool and ''plasma'' dynamics surrounded by an aqueous environment were monitored. Experiments were undertaken to characterize the attenuation of the laser beam in the water as a function of various focal length optics and depth of water. The effect of energy input conditions on the weld bead appearance and mechanical properties were also examined. The interaction of the laser beam with water produced a wave-guiding mechanism in which the focused beam instantaneously vaporizes the water and directs the beam on to the workpiece. The underwater weld beads exhibited sound microstructures over a range of weld energy inputs, mainly due to the formation of a ''dry region'' during welding. Metallurgical analysis of the welds showed a slight increase in hardness, though other post-weld mechanical strengths were similar to in-air results.

This report describes the computer simulation of two underwater nuclear explosions, Operation Wigwam and a modern hypothetical explosion of greater yield. The computer simulations were done in spherical geometry with the LASNEX computer code. Comparison of the LASNEX calculation with Snay's analytical results and the Wigwam measurements shows that agreement in the shock pressure versus range in water is better than 5%. The results of the calculations are also consistent with the cube root scaling law for an underwater blast wave. The time constant of the wave front was determined from the wave profiles taken at several points. The LASNEX time-constant calculation and Snay's theoretical results agree to within 20%. A time-constant-versus-range relation empirically fitted by Snay is valid only within a limited range at low pressures, whereas a time-constant formula based on Sedov's similarity solution holds at very high pressures. This leaves the intermediate pressure range with neither an empirical nor a theoretical formula for the time constant. These one-dimensional simulations demonstrate applicability of the computer code to investigations of this nature, and justify the use of this technique for more complex two-dimensional problems, namely, surface effects on underwater nuclear explosions. 16 refs., 8 figs., 2 tabs.

The use of remote sensing techniques such as adaptive optics and image restoration post processing to correct for aberrations in a wavefront of light propagating through turbulent environment has become customary for many areas including astronomy, medical imaging, and industrial applications. EO imaging underwater has been mainly concentrated on overcoming scattering effects rather than dealing with underwater turbulence. However, the effects of turbulence have crucial impact over long image-transmission ranges and under extreme turbulence conditions become important over path length of a few feet. Our group has developed a program that attempts to define under which circumstances application of atmospheric remote sensing techniques could be envisioned. In our experiments we employ the NRL Rayleigh-Bénard convection tank for simulated turbulence environment at Stennis Space Center, MS. A 5m long water tank is equipped with heating and cooling plates that generate a well measured thermal gradient that in turn produces various degrees of turbulence. The image or laser beam spot can be propagated along the tank's length where it is distorted by induced turbulence. In this work we report on the experimental and theoretical findings of the ongoing program. The paper will introduce the experimental setup, the techniques used, and the measurements made as well as describe novel methods for postprocessing and correction of images degraded by underwater turbulence.

A conventional camera can be adapted for underwater use by enclosing it in a sealed waterproof pressure housing with a viewport. The viewport, as an optical interface between water and air needs to consider both the camera and water optical characteristics while also providing a high pressure water seal. Limited hydrospace visibility drives a need for wide angle viewports. Practical optical interfaces between seawater and air vary from simple flat plate windows to complex water contact lenses. This paper first provides a brief overview of the physical and optical properties of the ocean environment along with suitable optical materials. This is followed by a discussion of the characteristics of various afocal underwater viewport types including flat windows, domes and the Ivanoff corrector lens, a derivative of a Galilean wide angle camera adapter. Several new and interesting optical designs derived from the Ivanoff corrector lens are presented including a pair of very compact afocal viewport lenses that are compatible with both in water and in air environments and an afocal underwater hyper-hemispherical fisheye lens.

Increased emphasis on maritime domain awareness and port security has led to the development of unmanned underwater vehicles (UUVs) capable of extended missions. These systems rely most frequently on well-developed side scan sonar and acoustic methods to locate potential targets. The Naval Research Laboratory (NRL) is developing biosensors for underwater explosives detection that complement acoustic sensors and can be used as UUV payloads to monitor areas for port and harbor security or in detection of underwater unexploded ordnance (UXO) and biochemical threats. The prototype sensor has recently been demonstrated to detect explosives in seawater at trace levels when run in a continuous sampling mode. To overcome ongoing issues with sample preparation and facilitate rapid detection at trace levels in a marine environment, we have been developing new mesoporous materials for in-line preconcentration of explosives and other small molecules, engineering microfluidic components to improve the signal, and testing alternative signal transduction methods. Additional work is being done to optimize the optical components and sensor response time. Highlights of these current studies and our ongoing efforts to integrate the biosensor with existing detection technologies to reduce false positives are described. In addition, we present the results of field tests that demonstrate the prototype biosensor performance as a UUV payload.

Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver. PMID:27157952

Defocus changes the visual contrast sensitivity function, thereby creating a complex curve with local dips and peaks. Since underwater vision in humans is severely defocused, we used optical theory and the phenomenon of spurious resolution to predict how well humans can see in this environment. The values obtained correspond well with experimental measurements of underwater human acuity from earlier studies and even point to an opportunity for humans with exceptional contrast sensitivity to see better underwater than the children in those studies. The same theory could be useful when discussing the visual acuity of amphibious animals, as they may use pupil constriction as a means of improving underwater vision.

Defocus changes the visual contrast sensitivity function, thereby creating a complex curve with local dips and peaks. Since underwater vision in humans is severely defocused, we used optical theory and the phenomenon of spurious resolution to predict how well humans can see in this environment. The values obtained correspond well with experimental measurements of underwater human acuity from earlier studies and even point to an opportunity for humans with exceptional contrast sensitivity to see better underwater than the children in those studies. The same theory could be useful when discussing the visual acuity of amphibious animals, as they may use pupil constriction as a means of improving underwater vision. PMID:15535363

Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems. PMID:26690172

Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems. PMID:26690172

Provides the apparatus setup, experimental method, necessary formulas, and references for three measurement experiments: (1) "Determine the Magnetic Induction of a Coil with a Hall Element"; (2) "Measuring Magnetic Force and Magnetic Field of Small Permanent Magnets"; and (3) "Measurements of Sound Velocity by Means of PZT" (piezoelectric…

Explains: (1) use of piezoelectric film (connected to power supply and oscilloscope) to reveal force-versus-time curves of bouncing balls; (2) use of bound wood splints or meter sticks to illustrate tree or tower stability; and (3) apparatus of co-axial discs with connected linking rods and suspended bobs to simulate waves. (DH)

Discusses how to build an inexpensive Young's modulus apparatus and also a lens with an adjustable focal length. Describes the demonstration of moving a peeled, hard-boiled egg in and out of a flask whose neck is slightly smaller than the egg. (MVL)

This section presents new ideas with regard to apparatus for teaching physics. The following four ideas are presented: (1) measuring speed of light (2) a poor man's barometer, (3) center of mass of a rotating object, and (4) minimizing glass breakage. (HM)

A borehole data transmission apparatus is described whereby a centrifugal pump impeller(s) is used to provide a turbine stage having substantial pressure characteristics in response to changing rotational speed of a shaft for the pressure pulsing of data from the borehole through the drilling mud to the surface of the earth.

Test apparatus is designed for determining tensile strength, modulus of elasticity, elongation, and thermal coefficient of contraction or expansion of uniformly shaped plastics, adhesives, and foam materials over temperature range of 700 to 90 K (800 to -300). Tests may be used in design quality control, and in evaluation of new adhesives and plastic materials.

Six different pieces of physics apparatus are described: Telsa Coil for instant ignition of sodium arc lamps, Timekube, Magnetic Maps of the United States, a slinky with vertical mounting, a wave generator power supply, and a long-period timer power switch. Price and supplier are included. (BT)

Disclosed is a superconductive electromagnet apparatus having a coil with a coiled conductor with a channel between adjacently disposed the paths of the coil conductor of which width is selected in accordance with amounts of heat produced at the corresponding portions of the coil section as viewed in cross section.

A microelectromechanical (MEM) friction test apparatus is disclosed for determining static or dynamic friction in MEM devices. The friction test apparatus, formed by surface micromachining, is based on a friction pad supported at one end of a cantilevered beam, with the friction pad overlying a contact pad formed on the substrate. A first electrostatic actuator can be used to bring a lower surface of the friction pad into contact with an upper surface of the contact pad with a controlled and adjustable force of contact. A second electrostatic actuator can then be used to bend the cantilevered beam, thereby shortening its length and generating a relative motion between the two contacting surfaces. The displacement of the cantilevered beam can be measured optically and used to determine the static or dynamic friction, including frictional losses and the coefficient of friction between the surfaces. The test apparatus can also be used to assess the reliability of rubbing surfaces in MEM devices by producing and measuring wear of those surfaces. Finally, the friction test apparatus, which is small in size, can be used as an in situ process quality tool for improving the fabrication of MEM devices.

Describes a simple apparatus for producing strip holograms with a number of slit-shaped exposures displaced along the vertical direction. The hologram maintains full horizontal parallax, but the slit aperture reduces the vertical viewing angle of the animated object. (Author/GA)

Describes four body-lever models (biceps, triceps, back lever when lifting, foot lever and Achilles tendon muscle) used in noncalculus physics courses. Instructions for constructing the wooden models are provided. Also describes an improvement on a centripetal-force apparatus so that it is easier to operate. (JN)

Presents two experimental set-ups. The first demonstrates the law of Malus using a pair of Polaroid polarizers and a monochromatic light source with an interference filter. The second describes a modification of Hilton's apparatus to demonstrate the effects of the magnetic hysteresis on an overhead projector. (CS)

Describes a coriolis simulator which uses a carbon paper trace technique and a simple specific-heat apparatus, emphasizing instructional considerations. Also indicates that a variac and an ordinary electric drill can be used to wind coil if a lathe or coil winder are unavailable. (JN)

The present invention is an automated pruning apparatus that requires little or no follow-up hand pruning and requires no sensors to avoid supportive trunks or posts. The present invention uses at least one pair of flat, close angled toothed, counter rotating blades. Woody branches are directed to the counter rotating blades first with a lifting arm and secondly by a quilled drum.

A positioning and locking apparatus including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member.

A borehole data transmission apparatus whereby a centrifugal pump impeller(s) is used to provide a turbine stage having substantial pressure characteristics in response to changing rotational speed of a shaft for the pressure pulsing of data from the borehole through the drilling mud to the surface of the earth.

An apparatus for traversing obstacles having an elongated, round, flexible body that includes a plurality of drive track assemblies. The plurality of drive track assemblies cooperate to provide forward propulsion wherever a propulsion member is in contact with any feature of the environment, regardless of how many or which ones of the plurality of drive track assemblies make contact with such environmental feature.

A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

Standing transverse waves in homogeneous strings have been demonstrated in lectures and used in experiments (called Melde's experiment). A variation to this experiment is discussed. Also discusses the use of the speed-of-sound resonance-tube apparatus to clean mercury. (Author/JN)

A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

A nuclear conversion apparatus is described which comprises a body of neutron moderator, tubes extending therethrough, uranium in the tubes, a fluid- circulating system associated with the tubes, a thorium-containing fluid coolant in the system and tubes, and means for withdrawing the fluid from the system and replacing it in the system whereby thorium conversion products may be recovered.

A positioning and locking apparatus are disclosed including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member. 6 figs.

Describes some laboratory apparatus and demonstrations; describes an electronic device to illustrate an octave synthesizer; shows how to get negative changes from an electrophorous; explains a body levers device to clarify the principles of moments and levers; and finally shows how to demonstrate acceleration in simple harmonic motion. (GA)

This patent describes borehole measurement apparatus. It comprises a tool adapted for connection in a drill string in the borehole through earth formations, first and second ultra-sonic transmitter means disposed diametrically opposed from each other in the cylindrical body, first and second ultra-sonic transducer means disposed in the cylindrical body, and logic means, processing means, and memory means.

Describes: how to measure index of refraction by the thickness method; how to teach the concept of torque using a torque wrench; how to produce a real image with a concave mirror; how to eliminate the interface effects of a Pyrex containers; and an apparatus to illustrate Bernoulli's Principle. (MLH)

A positioning and locking apparatus including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member.

Describes a few apparatuses and demonstrations for teaching physics under the headings: demonstrating resonance of the inner ear, constructing a potential well-hill for overhead projectors, rubber tube vacuum pump, improvement on the simple homemade motor, air track to demonstrate sailing into the wind, and center of gravity and stability. (GA)

A autonomous borehole data transmission apparatus for transmitting measurement data from measuring instruments at the downhole end of a drill string by generating pressure pulses utilizing a transducer longitudinally responsive to magnetic field pulses caused by electrical pulses corresponding to the measured downhole parameters.

The hydrogen breath test is based on following breath hydrogen levels after the administration of a carbohydrate (most commonly lactulose) to a patient with suspected small intestinal bacterial overgrowth. The test is based on the interaction between the administered carbohydrate and the intestinal bacteria. The resulting fermentation produces hydrogen. A positive breath test is based on a breath hydrogen rise prior to the expected arrival time in the highly microbial cecum. Despite renewed enthusiasm for breath testing in recent years due to associations with conditions such as irritable bowel syndrome, breath testing poses many challenges. In this argument against breath testing, several pitfalls that complicate breath testing will be described. PMID:26902227

...: Divers or underwater remotely operated vehicle (ROV). 71.50-27 Section 71.50-27 Shipping COAST GUARD... (ROV). To conduct the underwater survey portion of the AHE, you may use divers or an underwater ROV. (a.... (b) You may use an underwater ROV to conduct the underwater survey. The underwater ROV operating...

...: Divers or underwater remotely operated vehicle (ROV). 71.50-27 Section 71.50-27 Shipping COAST GUARD... (ROV). To conduct the underwater survey portion of the AHE, you may use divers or an underwater ROV. (a.... (b) You may use an underwater ROV to conduct the underwater survey. The underwater ROV operating...

...: Divers or underwater remotely operated vehicle (ROV). 71.50-27 Section 71.50-27 Shipping COAST GUARD... (ROV). To conduct the underwater survey portion of the AHE, you may use divers or an underwater ROV. (a.... (b) You may use an underwater ROV to conduct the underwater survey. The underwater ROV operating...

...: Divers or underwater remotely operated vehicle (ROV). 71.50-27 Section 71.50-27 Shipping COAST GUARD... (ROV). To conduct the underwater survey portion of the AHE, you may use divers or an underwater ROV. (a.... (b) You may use an underwater ROV to conduct the underwater survey. The underwater ROV operating...

...: Divers or underwater remotely operated vehicle (ROV). 71.50-27 Section 71.50-27 Shipping COAST GUARD... (ROV). To conduct the underwater survey portion of the AHE, you may use divers or an underwater ROV. (a.... (b) You may use an underwater ROV to conduct the underwater survey. The underwater ROV operating...

This patent describes an apparatus for imparting a seismic signal into the earth. It comprises seismic generator means for generating a seismic signal, comprising: an impact mass; and propulsion means for driving the impact mass to produce the seismic signal; coupling means, in engagement with the earth and engagable with the generator means, for transferring, into the earth, signals generated by the propulsion means driving the impact mass into engagement with the coupling means; lift frame means located above the coupling means and resiliently connected thereto; hollow housing means encompassing at least a portion of the generator means for inhibiting the entrance of water into the apparatus when used in an underwater environment and for confining noise produced by the apparatus when used in an atmospheric environment, comprising: a first end portion connected to the generator means; and a second generally annular end portion, the second end portion extending toward the coupling means; an annular connector member flexibly connecting the second end of the housing means to the lift frame means; and pivot means pivotally connecting the seismic generator means to the lift frame means.

A novel apparatus for reliably and selectively releasing a data acquisition package from an animal for recovery. The data package comprises two parts: 1) an animal data acquisition device and 2) a co-located release apparatus. One embodiment, which is useful for land animals, the release apparatus includes two major components: 1) an electronics package, comprising a receiver; a decoder comparator, having at plurality of individually selectable codes; and an actuator circuit and 2) a release device, which can be a mechanical device, which acts to release the data package from the animal. To release a data package from a particular animal, a radio transmitter sends a coded signal which is decoded to determine if the code is valid for that animal data package. Having received a valid code, the release device is activated to release the data package from the animal for subsequent recovery. A second embodiment includes floatation means and is useful for releasing animal data acquisition devices attached to sea animals. This embodiment further provides for releasing a data package underwater by employing an acoustic signal.

Global synchronization in a complex network of oscillators emerges from the interplay between its topology and the dynamics of the pairwise interactions among its numerous components. When oscillators are spatially separated, however, a time delay appears in the interaction which might obstruct synchronization. Here we study the synchronization properties of interconnected networks of oscillators with a time delay between networks and analyze the dynamics as a function of the couplings and communication lag. We discover a new breathing synchronization regime, where two groups appear in each network synchronized at different frequencies. Each group has a counterpart in the opposite network, one group is in phase and the other in anti-phase with their counterpart. For strong couplings, instead, networks are internally synchronized but a phase shift between them might occur. The implications of our findings on several socio-technical and biological systems are discussed. PMID:24256765

Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions. PMID:9769764

Apparatus for use in processing radioactive waste materials for shipment and storage in solid form in a container is disclosed. The container includes a top, and an opening in the top which is smaller than the outer circumference of the container. The apparatus includes an enclosure into which the container is placed, solution feed apparatus for adding a solution containing radioactive waste materials into the container through the container opening, and at least one rotatable blade for blending the solution with a fixing agent such as cement or the like as the solution is added into the container. The blade is constructed so that it can pass through the opening in the top of the container. The rotational axis of the blade is displaced from the center of the blade so that after the blade passes through the opening, the blade and container can be adjusted so that one edge of the blade is adjacent the cylindrical wall of the container, to insure thorough mixing. When the blade is inside the container, a substantially sealed chamber is formed to contain vapors created by the chemical action of the waste solution and fixant, and vapors emanating through the opening in the container. The chamber may be formed by placing a removable extension over the top of the container. The extension communicates with the apparatus so that such vapors are contained within the container, extension and solution feed apparatus. A portion of the chamber includes coolant which condenses the vapors. The resulting condensate is returned to the container by the force of gravity.

To characterize the performance of naval structures, underwater blast experiments have been developed. Martensitic and austenitic steel alloys were designed to optimize the performance of structures subjected to impulsive loads. The deformation and fracture characteristics of the designed steel alloys were investigated experimentally and computationally. The experiments were based on an instrumented fluid structure interaction apparatus, in which deflection profiles were recorded. The computational study was based on a modified Gurson damage model able to accurately describe ductile failure under various loading paths. The model was calibrated for two high performance martensitic steels (HSLA-100 and BA-160) and an austenitic steel (TRIP-120). The martensitic steel (BA-160) was designed to maximize strength and fracture toughness while the austenitic steel (TRIP-120) was designed to maximize uniform ductility. The combined experimental-computational approach provided insight into the relationships between material properties and blast resistance of structures.

Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. Methods and Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. Results: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. Conclusions: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins.

Breath analysis in respiratory disease is a non-invasive technique which has the potential to complement or replace current screening and diagnostic techniques without inconvenience or harm to the patient. Recent advances in ion mobility spectrometry (IMS) have allowed exhaled breath to be analysed rapidly, reliably and robustly thereby facilitating larger studies of exhaled breath profiles in clinical environments. Preliminary studies have demonstrated that volatile organic compound (VOC) breath profiles of people with respiratory disease can be distinguished from healthy control groups but there is a need to validate, standardise and ensure comparability between laboratories before real-time breath analysis becomes a clinical reality. It is also important that breath sampling procedures and methodologies are developed in conjunction with clinicians and the practicalities of working within the clinical setting are considered to allow the full diagnostic potential of these techniques to be realised. A protocol is presented, which has been developed over three years and successfully deployed for quickly and accurately collecting breath samples from 323 respiratory patients recruited from 10 different secondary health care clinics. PMID:25971863

The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

We studied the response of healthy volunteers to the delayed feedback generated from the breathing signals. Namely, in the freely-breathing volunteers the breathing signal was recorded, delayed by τ seconds and fed back to the same volunteer in real time in the form of a visual and auditory stimulus of low intensity, i.e. the stimulus was crucially non-intrusive. In each case volunteers were instructed to breathe in the way which was most comfortable for them, and no explanation about the kind of applied stimulus was provided to them. Each volunteer experienced 10 different delay times ranging between 10% and 100% of the average breathing period without external stimulus. It was observed that in a significant proportion of subjects (11 out of 24) breathing was slowed down in the presence of delayed feedback with moderate delay. Also, in 6 objects out of 24 the delayed feedback was able to induce transition from nearly periodic to irregular breathing. These observations are consistent with the phenomena observed in numerical simulation of the models of periodic and chaotic self-oscillations with delays, and also in experiments with simpler self-oscillating systems.

The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

The thesis proposes and explores an underwater lidar system architecture based on chaotic modulation of recently introduced, commercially available, low cost blue laser diodes. This approach is experimentally shown to allow accurate underwater impulse response measurements while eliminating the need for several major components typically found in high-performance underwater lidar systems. The proposed approach is to: 1. Generate wideband, noise-like intensity modulation signals using optical chaotic modulation of blue-green laser diodes, and then 2. Use this signal source to develop an underwater chaotic lidar system that uses no electrical signal generator, no electro-optic modulator, no optical frequency doubler, and no large-aperture photodetector. The outcome of this thesis is the demonstration of a new underwater lidar system architecture that could allow high resolution ranging, imaging, and water profiling measurements in turbid water, at a reduced size, weight, power and cost relative to state-of-the-art high-performance underwater lidar sensors. This work also makes contributions to the state of the art in optics, nonlinear dynamics, and underwater sensing by demonstrating for the first time: 1. Wideband noise-like intensity modulation of a blue laser diode using no electrical signal generator or electro-optic modulator. Optical chaotic modulation of a 462 nm blue InGaN laser diode by self-feedback is explored for the first time. The usefulness of the signal to chaotic lidar is evaluated in terms of bandwidth, modulation depth, and autocorrelation peak-to-sidelobe-ratio (PSLR) using both computer and laboratory experiments. In laboratory experiments, the optical feedback technique is shown to be effective in generating wideband, noise-like chaotic signals with strong modulation depth when the diode is operated in an external-cavity dominated state. The modulation signal strength is shown to be limited by the onset of lasing within the diode's internal

We report the case of a healthy 21-year-old woman who performed iterative breath-hold dives in relatively cold water, not exceeding depths of 5 meters but with "empty lungs." At the end of a dive, after experiencing an intense involuntary diaphragmatic contraction underwater, she presented hemoptysis followed by chest pain and cough. Chest radiography and computed tomography were performed 24 hours later, confirming the diagnosis of pneumomediastinum. The clinical course was benign: However, chest pain and effort dyspnea lasted for a few weeks. The pathophysiology of this accident may be explained by a combination of mechanisms involved in several clinical entities, namely pulmonary edema of immersion, pulmonary barotrauma and spontaneous pneumomediastinum. PMID:21721355

Volatile organic compounds (VOCs) in exhaled breath gas provide valuable information about the subjects' physiological and pathophysiological condition. Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid and online measurements of these substances. We present results of three studies illustrating the potential of breath gas analysis by PTR-MS in various contexts: long-time online monitoring of VOCs in sleeping subjects suggests that VOC profiles are related to sleep stages. Analysis of VOC concentrations in the breath of carbohydrate malabsorbers emphasizes the role played by bacteria in the gut. Finally, we demonstrate the large intra- and intersubject concentration variability of VOCs by considering one particular mass.

...This notice announces the planned revocation of all Technical Standard Order authorizations (TSOA) issued for the production of Underwater Locating Devices (Acoustic) (Self-Powered) manufactured to the TSO-C121 and TSO-C121a specifications. These actions are necessary because the planned issuance of TSO-C121b, Underwater Locating Devices (Acoustic) (Self-Powered), with a minimum performance......

...This is a confirmation notice for the planned revocation of all Technical Standard Order authorizations issued for the production of Underwater Locating Devices (Acoustic) (Self-Powered) manufactured to the TSO-C121 and TSO-C121a specifications. These actions are necessary because the planned issuance of TSO-C121b, Underwater Locating Devices (Acoustic) (Self-Powered), minimum performance......

Due to the major obstacles originating from the strong light absorption and scattering in a dynamic underwater environment, underwater optical information acquisition and processing suffer from effects such as limited range, non-uniform lighting, low contrast, and diminished colors, causing it to become the bottleneck for marine scientific research and projects. After studying and generalizing the underwater biological visual mechanism, we explore its advantages in light adaption which helps animals to precisely sense the underwater scene and recognize their prey or enemies. Then, aiming to transform the significant advantage of the visual adaptation mechanism into underwater computer vision tasks, a novel knowledge-based information weighting fusion model is established for underwater object extraction. With this bionic model, the dynamical adaptability is given to the underwater object extraction task, making them more robust to the variability of the optical properties in different environments. The capability of the proposed method to adapt to the underwater optical environments is shown, and its outperformance for the object extraction is demonstrated by comparison experiments.

The susceptibility of welds to stress corrosion cracking (SCC) is enhanced by the surface residual tensile stresses generated by the typical welding process. However, underwater plasma transferred arc (PTA) welding has been shown to produce compressive surface residual stresses, an encouraging result if repairs of cracked boiling water reactor (BWR) components are to be made without further endangering them to SCC. This program was designed to verify that underwater PTA welds are resistant to SCC and to determine if underwater PTA welding could mitigate SCC in potentially susceptible welds. This was achieved by exposing various welds on solution annealed (SA) and SA + thermally sensitized 304 stainless steel at 25 C in a solution of 1.5 gm/liter of sodium sulfide added to 0.05M sodium tetrathionate, titrated to a pH of 1.25 with H{sub 2}SO{sub 4}. The autogeneous welds were produced using gas tungsten arc (GTA) and plasma transferred arc (PTA) welding under atmospheric conditions, and PTA welding underwater. After 1 hour of sodium tetrathionate exposure, GTA and air PTA welds exhibited SCC while the underwater PTA weld heat affected zones were more resistant. Underwater PTA welds bisecting a GTA weld eliminated the cracking in the GTA weld heat affected zone under certain conditions. The lack of IG cracking in the region influenced by the underwater PTA weld is consistent with the measurement of compressive surface residual stresses inherent to the underwater welding process.

Astronaut Edwin Aldrin, pilot for the Gemini 12 space flight, assumes a rest position during underwater zero-gravity training. The underwater environment creates similar conditions to those found in space. He is secured to the adapter section of the spacecraft by special foot plates.

In this study we investigated the effects of underwater exercise in warm water (34 degrees C) on physiological and psychological relaxation. Eight healthy young men (aged 20-26 years) volunteered for the experiment. The experiment consisted of the following three successive segments: a pre-exercise period of 20 min, during which the subjects rested in a semi-supine posture with their eyes closed for the final 10 min; an underwater exercise period of approximately 60 min, during which the subjects performed gymnastic exercises or aerobic dancing with occasional movements or jumping; a post-exercise recovery of 20 min, which was similar to the pre-exercise rest period. We compared the relative power values (power %) of the electroencephalogram alpha bands (8-13 Hz) and profile of moods states (POMS) before and after the underwater exercise. We also estimated the percentage of maximal heart rate (%HRmax) throughout the experiment to ascertain the intensity of the underwater exercise. The results of %HRmax indicated that the intensity of underwater exercises practised in the experiments ranged from low to moderate. The power % of EEG alpha bands had increased significantly after the underwater exercise compared with the pre-exercise rest (P<0.05). From the POMS results, we observed that positive mood (vigour) increased and negative mood (tension and anxiety, depression and dejection) decreased significantly after the underwater exercise (P<0.05). This study found that the subjects showed increased physiological and psychological indices of relaxation after underwater exercise. PMID:10483793

An apparatus for protecting diagnostic equipment from blast damage by rapidly interposing a shutter between the equipment and the blast area. The apparatus comprises a sensor for sensing a trigger signal associated with the blast and for converting it into a voltage pulse. The voltage pulse is received by the first end of a firing pin. A pressure chamber holds a gas under pressure. The second end of the firing pin is located inside the pressure chamber and is located above a foil member covering an orifice. When the voltage pulse reaches the second end, a point-to-plane discharge ruptures the foil, allowing the gas to enter a drive housing and quickly move a drive piston away from the foil. A drive rod connects the drive piston to a shutter and as the drive piston is moved down, the shutter moves into a closed position, protecting the equipment from debris.

A method and apparatus for removing material and components such as the lens from an eye is described. High speed rotary cutting members at one end of a rod macerate the lens while an annular tubing disposed around the cutting members vibrates ultrasonically to coact with the cutting members in macerating the lens. At the same time, a liquid is supplied to the chamber behind the cornea of the eye. Spiral grooves extending along the rotating rod from the cutting members evacuate the liquid and the macerated material from the eye. An alternate embodiment of the apparatus includes a tube through which liquid is supplied to the operative site of the ultrasonically vibrating tube and the cutting members in the area of the lens.

Mud choke apparatus is disclosed, and the preferred embodiment has the form of a hollow, tubular body receiving a mud flow introduced from a lateral port, the flow being directed through an axial passage and past a valve seat. The valve seat is a replaceable, hardened metal liner and is formed with a gradual taper so that the mud flows from the large end through the tapered, smaller end. Thereafter, it flows out of the body through an axial opening. The flow of mud is throttled by a tapered, hardened plug serving as a valve element which is received into the valve seat. A hydraulic cylinder and piston with a connecting rod move the plug. The plug has a surrounding, perpendicular shoulder which seals and seats against a shoulder on the insert to fully close the throttling valve apparatus. Flow is choked by inserting the tapered plug with controlled clearance into the tapered valve seat.

A multipurpose, collapsible, shower apparatus for use almost anywhere but especially adapted for use in places somewhat remote from civilization such as recreational vehicles, campers, the outdoors, space vehicles and the like where there may be a limited amount of water or other liquid. The collapsible shower apparatus includes a curtain assembly having an inner wall, an outer wall and a porous element for separating the inner and outer walls; a series of spaced hollow hoops connected by one or more sets of hollow tubes (manifolds); one or more nozzles connected to and in communication with at least one of the hollow hoops; a source of fluid under pressure in communication with at least one of the hollow hoops; and a suction pump for withdrawing fluid from the interior of the curtain assembly.

The invention described relates to an apparatus for providing a selectively humidified gas to a camera canister containing cameras and film used in space. A source of pressurized gas (leak test gas or motive gas) is selected by a valve, regulated to a desired pressure by a regulator, and routed through an ejector (venturi device). A regulated source of water vapor in the form of steam from a heated reservoir is coupled to a low pressure region of the ejector which mixes with high velocity gas flow through the ejector. This mixture is sampled by a dew point sensor to obtain dew point thereof (ratio of water vapor to gas) and the apparatus adjusted by varying gas pressure or water vapor to provide a mixture at a connector having selected humidity content.